Looks like an Albino (white) Cory to me, like the one Saed posted.
They arent exactly hardy (to answer you're first question), as corys are prone to bacterial infections, but if you keep your water quality in check, they can be great little fish.
They are a shoaling species, so i'd get 3 or more so they have company, and they are fine with you're guppys and platys.