Personally, i've found amano shrimp to be a lot more prolific cleaners that ghost shrimp. they also have, in my opinion, more interesting markings. i think with those and possibly a nerite that you'd have all the cleanup crew you needed. i've had good luck thus far with just 2 otos in my 8 gallons. only concern i would have in a 5 is that they might run out of natural food. i end up supplementing mine with a mini algae wafer a couple times a week just in case.
just my 2c