Shrimp are not a good choice for any tank with Angelfish. Large Bamboos perhaps but you do not have enough cover. I'd go with crayfish--large crayfish or fully grown dwarfs.
I'm planning on getting or making a little cave and also getting live plants for the tank... I'm still trying to decide if I'm going to get some Cory's since the Swordtails spend a good amount of time on the lower part of the tank... I wanna have it pretty balanced...