Ah, yes, IPSF- where you can get 6 bristleworms for $20. I've heard good things about them, but their prices for things you're likely to get free on coral frags are pretty silly.
Court jester gobies sift sand and pick at algae and copepods. They're definitely best in an established tank with a lot of things to pick at. A neon goby would be an excellent choice- they're hardy, colorful, and fun to watch. They do only live a couple years, though.
A clownfish would be fine in terms of its own need for space, they're not super active, but they do get aggressive as they mature. There might not be enough room for anything else in there with it.
My pick for a 10gal would be a small shrimpgoby like a yasha haze, Wheeler's, or antenna goby, plus a candycane pistol shrimp. Amazing symbiotic pair, great fun to watch, and not aggressive at all. You could put pretty much any other (10gal suitable) fish you like with it, except another shrimpgoby. I'm also partial to clown gobies, if you can find one that's eating well.
In a 10gal, you should expect to be able to stock 2 nano (3" or under, preferably slender) fish. If you pick very small fish like tiny gobies and blennies, you could do 3.