A dwarf puffer (possibly even 2) should do fine in your planted tank. I've found - mostly through forum advice - that kuhli loaches do well with them. I have 6 dwarf puffers and 4 kuhlis in a heavily decorated (artificial) 29g, and they all do well together.
Redneck, figure-8 puffers aren't the same as Indian dwarf puffers. Dwarf puffers max out at less than an inch, but will also eat snails.
150g long S Amer cichlid; 90g C Amer cichlid; 90g Malawi cichlid; 40g Tanganyika cichlid; 29g "Shellie" cichlid; 29g Pea Puffer. 6,500g koi/native catfish pond; several smaller ponds