Yep, you can mix the bee (Cardinia) and Rili (NeoC) .. no chance of cross breeding. 30 of each should work .. Rili's are just a color morph of RCS so they're small ... bee's also stay small so Bio-loads shouldn't be an issue. However keep in mind that although they have small bio-loads, shrimp are fairly prolific breeders. I don't think you want your tank to have that "shrimp Infested" look. I've seen tanks on youtube where the WHOLE substrate is just shrimp ... plus hundreds swimming around the tank. On the flip side, lots of shrimp means you can sell them to members and or to local LFS's.
I'd encourage you to reconsider Amano ... I love them. They're always active, are a nice size and always eating algae. Plus ... even though they are Cardinia, they won't breed with your Bee.