most moss should do! xmas moss, flame moss, mini pellias. if you want a carpet, you can do monte carlos, they'll grow slower and prob not as green/dense as with co2, but they'll thrive and be ok.
I'd recommend the peat and some have plenty of ferts in them already so it'll work well. If you more concern with PH and such for neos or shrimps in higher ph etc, you can always add in rocks like seiryu that tend to buffer higher. Or do a mix of sand + peat, peat where you are going to put the plants. Upaqua soil also seems to be ok, doesn't mush like ada aquasoil, doesn't leech ammonia and is easier to manage with. For some, it doesn't really buffer the PH low as advertised.