Think i could do:
3 emerald dwarf rasbora
3 killifish or 3 celestial pearl danios
6 red cherry or blue velvet shrimp?
Should work.
I'd skip blue velvet as unless they come from a reputable place they will be very washed out blue. Red Cherries are a lot easier to find with nice red color. Even brighter are the fire reds, show up nicely on a dark substrate (ditto the fish you're looking at).
Before you get the CPDs or dwarf rasboras, confirm they are OK on some kind of dry food like new life spectrum or similar; otherwise, if they're freshly wild caught (I believe most are) they may be finicky about eating. Shrimp will eat whatever - sometimes I feed mine, sometimes not - they eat microorganisms in the tank - but they love algae wafers.