flamingo if you can't find them look into these other aquatic salamanders
Amphiumas-Large/eel like.Not sure if they have gills but they're aquatic
Axolotls- Smaller and usualy more common aquatic salamander. Albinos as well as natural black/brown colorations are available. Can be VERY easily obtained by scientists or teachers from universities like this one
http://www.ambystoma.org/AGSC/ they don't sell "pets" they sell living research material, but any K-12 teacher can get the "live material" for you
Hellbenders-For an oddball lover who is up for the challenge of finding one on the market though that might be harder then a mud puppy to find as they're becoming endangered
Sirens- Cool little "salamander". They lack hind legs, have very small front legs, and are aquatic. A bit of a challenge to find, but nto impossible