Im just a youngan to the fish game but im going to be adding some coolie (also spelt with a k but sounds the same) loaches. I think they look real good - black and orange stripes and a snake like body shape, very passive too. Theres quite a few that would fit in a 30. Try
http/www.liveaquaria.com/product/scateg....d=21&pCatId=885 for info on a few common ones. Clowns are popular but they grow pretty big, but slow, so you could prob havae some if you have plans for a bigger tank later.
Botias seem to be 2-4 inches (the ones ive seen) when grown an possibly a good choice.
Sure someone with real experience will come along soon to help.
another good site to check out is
http/www.fishprofiles.com/
good luck finding your loaches.
C