Sorry, away from the computer for a few days there. I wouldn't be doing just Rasboras (we have 13 now). We're thinking of moving our Glass Catfish in (only have five of them ATM, would add three to five more), and adding some bottom dwellers as well. Maybe yoyo's, and some kuhli's. We've got four upside-down catfish that need a home as well, so they may end up here as well (with possibly four new friends).
I'm interested in rasboras when I ultimately upgrade to a 75 gallon. I'm thinking of 3 pearl gourami, 3 clown loaches, a few smaller loaches (khulis, horse-faced, hillstream) and then a school of rasboras. How many rasboras might be a good target size for that kind of 75 g Asian fish community tank?