I think I would. In an 8 team league, you aren't as likely to make a run for some of the prospects that get called up in the next month and I don't see you getting much better of a player than Wandy. On top of that, you could use the SP. So yes make the move.
"In the beginning the Universe was created. This has made a lot of people very angry and has been widely regarded as a bad move."- Douglas Adams
Your pitchers are good. Wandy does represent an upgrade over someone like Peavy, but is it worth the #1 waiver claim? I think not, and my reason is that your in an 8 team league. There will be other pitchers of Wandy's caliber on the waiver wire at some point this season, assuming normal stupidity in the league. Also, being an 8 team league, most teams probably have good pitchers. Try to wait until after the waiver period and pick him up like a normal FA. I doubt someone puts a claim on him while he's on waivers, and if they do so be it. You won't be hurting.
Is Wandy worth a #1 waiver in an 8 team league? No, definitely not. He might not even get picked up from waivers in an 8 team league, so if he's sitting there as a FA after he clears waiver, then we can talk.