I do think he's the most NBA-ready of the overseas prospects. I fully expect LJC to come over for contract reasons, but it wouldn't surprise me to see Thomas be the MVP of the summer-league team and force the Spurs to give him a camp tryout. He looks a lot more athletic now, and if he's kept up his skill level from last year, he'll be a decent bench guy.
So assuming he and LJC come over, I don't see the Spurs having room for a small-forward. That would be four on the roster not counting Green's ability to play there. A scoring guard would make sense, as would a BPA big. Maybe the Spurs will be able to trade Thomas' rights for a decent asset.