Not counting the many brackish puffers sold as freshwater, here's a list of the more common FW puffers sold:
Auriglobus modestus - Golden puffer
Carinotetraodon imitator (travancoricus)- Dwarf puffer
Carinotetraodon irrubesco - Redeye puffer
Colomesus asellus - Peruvian puffer
Tetraodon fluviatilis - Green puffer (better in brackish to marine)
Tetraodon lineatus - Fahaka puffer
Tetraodon mbu - Giant Congo puffer
Tetraodon miurus - Congo puffer
Tetraodon palembagensis - Hong Kong/Dragon/Humpback puffer
Tetraodon turgidis - Brown puffer
There are many more FW puffers but, they're not frequently seen in a LFS. And, from this list you will find wide variations. The smallest species can live in communities in small tanks and only reach around an inch. The largest on the list (Mbu) can be kept with other fish but reach a size that needs a giant tank starting at around 300gal. Some are active and some spend most of the time buried in the substrate.
Check out
www.puffers.org and other puffer sites to find what you like and can house. There are a lot of puffer keepers here. We'll be glad to help with your choices.