Live bearers really do use the whole tank, too, and they might work with a pair of kribs here. With this size, you could possibly do an earth-eater, too.
With this height, I might suggest more communities of smaller fish rather than big, big fish, unless you wanted to do something like a pair of Jack Dempseys or something rather cool like that. A 47 might be on the smaller side for Dempseys, but it's likely close.