If you're in jersey, have you been to ridgewood aquarium? small store, but they had a lot of plant variety the one time I went there.
If you buy RCS from any pet store, you are most likely only going to get females. I know from personal experience that pacific aquarium in NYC chinatown only stocks females (whether they know it or not).
I have two ada mini-S, which are 3.5 gal (true water volume is about 2.5 gal). One currently stocked with 3 cardinal tetras and 3 RCS (only males left, btw), and the other thank with a betta.