they can live well with other oddballs... but you need a fairly large tank for them, I'd recommend atleast 75gallons for a temperary home, a 100-120gallon tank would be better suited as it would last for a fairly longer amount of time than a 75gallon tank... Cane should really answer this he's got his with an arowan, a florida gar, a fire eel (or some other type of eel) and something else...
But IMO don't get it unless you've got a 120gallon tank for it as even the smaller species still can reach somewhere around a 16" disc...
rays can live happily with lots of different types of fish but i agree with k.o.d,puffers can be unpredictable and aggresive and they are armed with a powerful bite.i would not try this combination.
yeah, i think that your only option in terms of freshwater puffers would be a mbu--which are still pretty unpredictable. the only other FW puffer that can be considered (potentially) community-safe is the SAP and even the largest of those would be a quick snack for a ray.
arrowanas are pretty popular tankmates for rays (although avoid jardinis) and i know that t1karmann has some gorgeous datnoids with his. he also used to keep some nice-looking panda uarus (a rather placid type of cichlid) in there. i think other people have also tried some of the more peaceful geophagus with some success.
Puffers like to lie on the bottom of the tank to sleep, and unless they are very large id guess theyd be a meal for the ray if it envelopes them. A MBU would probably be ok but youd need a VERY large tank.
With rays, you can keep anything that is bigger than its disk diameter, is peaceful and, if it bit the ray, could not do any damage. For that reason i would rule out any type of puffer.
what exactly is "ray rashed"?i would not keep angels with rays either even though i will probably never have rays,its just suttin you shouldnt do.its like putting a neon in a shark tank.it will just end bad