OK another noob question here:
I've heard inquisitors mentioned with respect to being included in a SoB army. Where do I find the datasheet for these, and what are the rules for integrating them into a battle forged SoB army without losing the varioius orderly buffs, sacred rites, etc?
There are two ways to use Inquisitors with sisters: attach one Inquisitor to any of your existing sisters detachment as a slotless HQ or take an allied Inquisitorial detachment (which could include no more than a single Inquisitor). You could also do both of these things, allowing you two field two Inquisitors without taking multiple Inquisition detachments; this also allows one of your Inquisitors to have a retinue. I'll start with things that are common to each of these approaches, then I will talk about the specifics of each.
So the reason Inquisition and Sisters are thematically related is that once upon a time in GW Lore, the SOB's role as chamber militant of the Ordo Hereticus was front and centre. These days, that lore has been shunted to the background in order to create design space for the Ecclesiarchy, but the connections are still there in the lore- they're just more subtle. From this perspective, Greyfax and Karamazov are excellent named choices for inclusion in a Sisters army. Aesthetically, Greyfax resonates with the feminine mystique of sisters, but Karamazov resonates with the aesthetic of both Penitent Engines and Mortifiers. It is a dream of mine to one day field Karamazov with three full squadrons of morties and pennies, including all the anchorite upgrades. A generic Hereticus Inquisitor is also nice, especially in Crusade, where the customization potential is greater than it is with named characters.
A third fluffy choice is Draxus- especially if you are playing in the Pariah setting. My sisters are such purists, they could not tolerate Stern's Eldar buddy without Draxus there to run interference for him like the radical that she is. The relationships here are cannon, as is the coneection between Greyfax and Celestine via Gathering Storm.
Though I've walked you through the "Fluffiest Fit," it's worth noting that there is no reason that Sisters can't ally with less fluffy Inquisitorial choices.
Either way, consider the Inquisition strat Arbiter of the Emperor's Will. This allows any Inquisitor who is not your Warlord to take a WL trait, and if the Inquisitor is generic, you also get a relic for free. In Crusade, any character can take a WL trait anyway, so in that game, Arbiter is only worth the requisition point if the Inquisitor is generic; if the Inquisitor is named, it makes just as much sense to just burn the RP for the WL trait. Greyfax's WL trait is great for synergizing with close combat and drop units because she can lock survivors into combat which protects your Sisters units from being shot to pieces in the enemy's following turn. Karamazov's WL trait isn't as good for sisters, because they're already pretty good at the morale game. Kyria's trait is good, but it only applies to her, so there's no synergy with any particular Sisters unit.
The Execution Bombardment strat is crazy expensive, but it's a powerful option in big games where you have CP to spare; Strategic Excrutiation is cheap, and excellent for small games where extra CP give you a huge advantage, especially when combined with the Mental Interrogation psychic power, and even more especially when we're dealing with Greyfax and Bloody Rose drop units. Other honourable mentions include the Alpha Class Psyker strat and the Psychic Mastery WL Trait; these help make up for Sisters inherently weak psychic offense game. All of these options work well, no matter how you incorporate the Inquisitor.
Okay, now let's talk about the characteristics that apply only when you attach Inquisitors to existing SOB detachments.
In this scenario, it isn't possible to take other Inquisition units such as Acolytes, Jokaero or Daemonhosts (unless you sneak one in via Eisenhorn's special rules- and in my fluffy, pure army, that's heresy). This can cut down on your ability to Sniper Proof your Inquisitor with Acolytes. Celestians can only bodyguard for <Order> characters. Personally, I think that should be changed to Sororitas and Ministorum at the very least; this would allow them to bodyguard for Hospitallers, Dialogi, Missionaries and Preachers. I'd also like to see them bodyguard for Hereticus, but like I said, they de-emphasized the Order Militant relationship, so this last wish is very unlikely. That means Acolytes are any Inquisitor's only protection against snipers, and you can't take acolytes for attached Inquisitors.
In this scenario, the Inqusition Strat: To the Exclusion of All Else is particularly useful as it grants the Inquisitor's Quarry rule to an Imperial unit, which helps the Sisters FEEL more like a Chamber Militant. Ditto for the Warding Incantation psychic power, but that's a Malleus power. By the same token, powers that affect only Ordo units are useless, since the Inquistor(s) using the power are the only Ordo units on the table. This takes out quite a few options- the Psychic Pursuit and Psychic Veil psychic powers and the Clandestine Operation Strat- all of which are pretty awesome, and will be missed if you choose this method to include an Inquisitor.
They final benefit of including an Inquisitor this way is that you get to keep BOTH your Order traits AND your Sacred Rites, though neither will apply to the Inquisitor.
Now let's talk about including an allied Inquisition detachment. First, it kills your Sacred Rites, but it does leave Order Traits intact. Obviously, it costs you CP to include this detachment, and it will have to be a Vanguard.
Obviously, it puts the Ordo specific buffs mentioned above back on the table, and all of the buffs listed above as being particularly suitable for attached Inquisitors are still equally effective for allied detachments. But for me, what really shines in this method is what happens in Crusade games, where any character can have a WL trait. Because ALL Inquisition units either are characters or have the option to be characters. That's right, WL traits for your Jokaero and Solo Acolytes, as well as your Daemonhosts if you're enough of a Heritic to include them.
The final approach, a Hybrid between allied detachment and attached Inquisitors allows you to tweak your force to get as many of the advantages land mitigate as many of the disadvantages listed above. For example, if both Inquisitors are of the same Ordo, Acolytes from the Inquisition detachment can be used as bodyguards for the attached Inquisitor.
A final note: in either system, you can include more than one Ordo in an army, but doing so is only really fluffy under certain circumstances; Hereticus + Xenos is fluffy against GSC. Malleus + Hereticus is fluffy for a Chaos army that includes both Cultists and Daemons. It's harder to fluff Xenos + Hereticus, and it's very hard to fluff all three together.