Exodons are cool, but limit your options for tankmates.
I really like my argenteus tetras (tetragonopterus argenteus). They are active, tight schoolers, smaller than silver dollars but larger than most of the common tetras available. They won't pick at other fish like exodons will, but will still swarm live food and behave as a pack of mini-piranhas.
Not a great picture but my pack can be seen in the middle of the tank:
Another medium sized predatory tetra option is rhoadsia altipinna. They are gorgeous fish, but are usually pretty scarce and relatively expensive as well.
Of course if youre trying to stay economical, a large school of tiger barbs would make for a great tank. Ime their behavior changes and they become much more interesting fish when in a group of 20-30 or more.
Check out the wet spot in oregon for prices on exodons if you still like them. It seems to me they're usually $8-10 each at a decent size, but of course you'll have to pay shipping as well.
