CPD's don't do well in anything less than a 10g. They need the swim room and larger groups.
Consider the Microrasbora Nana (microdevario nanus) as they stay really small 1.5cm.
Spotted rasboras not sure on depends on the size. probably not many.
Start with a dozen or so shrimp once tank is about 60 days old and you should have lots in no time.
Fluval Spec III Shelf!
"C'mon, they're just plants, man, no big deal -- try some"