Caridina japonica/Caridina multidentata (japonica shrimp, amano shrimp, yamato shrimp, algae shrimp are all common names). They do well in a wide range of params from soft to hard water. They can also tolerate a wide range of temps from low 70's through mid 80's. They get about 2" long. Their lifespan is approximately 3 years. They are a low order shrimp which means altough they will carry eggs and the eggs will hatch into larvae in freshwater, teh larvae will not develop into shrimp without being transitioned through brackish water. They are entirely plant and fish safe and very easygoing shrimp despite their large size (for dwarf shrimp anyway). They are easy to supplement as well readily taking flake or pelleted food. they will eat filamentous or biofilm algaes.
As to where to buy them, i sell them or alot of times they can be found in LFS