I would have to say Dwarf puffers would be a bit easier to keep, mostly because you don't have to worry about keeping the Sg constant (FW so no Sg at all) like you would for Fig 8's.
Sorry bout that, Sg stands for Specific gravity, a fancy term for the salt concentration in the water. When you see someone posting that their tank is at 1.005 Sg, that means it is light brackish, only a little salt in the water (I think 5 parts/thousand) , as opposed to Full salt water or Marine (I believe is 1.025) while fresh water would be 1.000 Sg (no salt)
