I fully expect the Spurs to draft and stash a euro player, but there are some collegiate guys that are intriguing that could possibly be available at the end of the first/early second (if the Spurs trade down). Just for fun, here's some guys that could be available.
Mitch McGary is a name that has been rumored to have some serious interest from San Antonio. He appears to be built like Baynes, 6'10" and strong. He's got good effort, runs the floor well, and is a very good rebounder. Offensively it seems like he's decent running the pick and roll. He seems pretty limited defensively though, as his blocked shot numbers aren't very impressive for a college big; I'm fully aware that you can be an excellent defender and not put up big block numbers, see Splitter. However, I've watched very little of this guy, so I can't speak much to his defense other than his stat line. He wouldn't be a bad pick, and with the pick and roll heavy offense we run, we can afford to have a big that can do that well but is other wise limited offensively.
Glen Robinson could very likely be gone before pick 30, but I've seen some projections where he falls after 30 as well. He's got good athleticism, can finish at the rim, and is a pretty good defender. His biggest knocks are his ball handling and shooting, but with Chip Engelland and his body of work (Tony Parker and Kawhi, namely), I'm pretty confident we could make his jumper more than serviceable. IMO, he'd be an excellent pick for a 3 and D guy that could spell Kawhi, with the potential to develop into more than just a role player.
Another guy I like is Spencer Dinwiddie from Colorado. He's 6'6" and did most of the ball handling for the Buffs. He shot over 40% from 3 and average almost 4 assists per game. Some scouting reports I've read say he has enough quickness to be an average defender. However, he tore his acl this year so his athleticism might not recover. He'd certainly be worth a shot if we could get him in the second round.