No idea about dealers in Mexico. Try a reptile show or local pet stores.
As for Panchlora nivea I only know of their giant morph in the hobby as the only other green roach. But there are plenty of other "pretty" roaches out there. Take the "Halloween" hissers or the glow spot roaches, both are pretty in their own unique way. Personally I think the death heads cockroach (Blaberus craniifer) is by far one of the prettiest roaches. You'll be limited on color ranges but there are some cool ones out there for sure.