That looks pretty sweet, have you got a full tank shot?
As for adding fish, i guess it depends if you would prefer to have a large colony of shrimp or not, since even most small fish will have mouths large enough to eat baby shrimp, and unless you have a lot of shrimp, or a lot of cover for the babies, it may take a while to build a decent sized colony...
I have Two shrimp tanks, 135gal cichlid, and 35gal community tank. Just started with shrimp a few months back. I would stick with the shrimp in that tank. Add more shrimp.