Ooh! If you don't want breeding, you can ask for all one gender. It's a little hard to tell when they're juvies, which is the age most places ship them.
If you want to wait for weather to warm, Bpophoto has a load of cherry red males. Apparently, 75df results in a lot of males.
Amano shrimp require brackish water to hatch their eggs, so they won't be able to reproduce if you decide to go with those instead.