2 Figure 8's BW
2 South American Puffers FW
6 Dwarf Puffers FW
Targets, Abei, Fangs, Turgidus, all FW only 1 though as they wont tolerate tankmates.
A pair of red-tail red eye puffers FW
There's probably a few more but thats just off the top of my head.
I love puffers ! The gsp are a favorite of mine, but I would go for the figure 8's they are sweet! I also think that they will be much easier to keep in your size tank!