25 gallon cube
Wishlist :
1 - Firefish goby
1 - Whiteray shrimp goby
1 - Blackray shrimp goby
1 - Benggai Cardinal (would this size tank be too small?)
Your bio-loading should be fine, but normally two shrimp gobies will not work, especially in a small tank, because they will not get along. Usually one will steal the other's shrimp (I do not know how). The exception is a mated pair.