I have gone into the Buyer's Guide to add the following:
Update: I wouldn’t buy anything right now. The future of Space Wolves units is too much in flux right now, as we’ve seen from multiple recent leaks on unit characteristics and weapon profiles. We also know that the points increase for units and weapons that we just had with the release of 9th edition are all going to change again. The new 9th edition Space Marines codex is scheduled to be released in October, and the Space Wolves supplement should follow soon after. Only then will we have a better, fuller, picture of unit effectiveness and efficiency. Until that point, I wouldn’t recommend that anyone make new purchases - give it a couple months for the new books to drop, and for the dust to settle on the impact of the major changes that we all now know are coming.
The recommendations below were good, in my opinion, for the final months of 8th edition, and the initial release of 9th edition. However, we don’t now know which, if any, of the units below will be the right ones to move forward with in planning out your new Space Wolves army for the future. So, my advice to everyone right now is to be patient, wait for the full picture to be revealed, and then we’ll all go from there. At that point, I will update this Guide to make it useful once again.