Cool shrimp! I must say, you have VERY good taste in stocking, I want to stock my tank like that! If I was you thought I wouldn't get sand, it looks very unsightly with the bristlenose poo all over it, i've got three of them and they are messy little buggers, even with weekly gravel vacs. I'd say a black background, as it looks much better, as i've had experience with both, blue, black and planted, black looks much better against both the fish and the plants. Also, i'd go for a black gravel, it also makes the plants and fish stand out, and maybe even get something like eco-complete or flourite to put under it for your plants if you decide to get more?
Neal