I'm skeptical about Wilcox. Guy is not basketball-smart, he's lazy, and he's no shot-blocker. He used to be athletic, but if you've seen him this season he looks slow and overweight.
I'd rather Collison who, whilst unspectacular, is a solid lunchpail-type worker. He goes to the boards, plays tough post D, and has a solid midrange jumper, but he's also not really a shot blocker... he's basically a younger, quicker version of KT.
Come to think of it, neither of these guys truly fills our need, although either could potentially blossom or crash in the Spurs' system. End of the day, we're talking about help this year, so I take the smarter guy (more apt to learn our system quickly), and that is Collison.