If the Jazz go for a "win-now" move, I hope (unless it's something completely surprising) that they manage to do it on a buy-low basis. I think that means Collins is more likely than OG, but I'm more skeptical than some that Collins can really be had at a super-low price.
OG fits to some degree. Obviously, his defense would be great, and his general versatility is a huge plus. But I'm a little worried that he might get slotted into (or expect) more of an offensive load than he should be carrying. I also think his price-tag is likely to be too high.
As for Collins, if he can be had at a reasonable price, I'm more interested than I was when I first heard about the Jazz's interest. He's basically a 20/10 guy per 36 for his career, with arguably nearly as good on-off numbers as OG. I still don't trust his defense as much as some do, but I think I'm no longer in the camp that he's a minus on defense. If the Jazz feel like they can fit him in, I'll give them the benefit of the doubt (given the surprising--to me--success they've had this season at fitting the likes of Clarkson, Sexton, Beasley, and so on into a cohesive offensive team).