Not that it matters much, but you should determine if you are going to do a species only tank or try to keep fishies with them.

There are several small 10g filters you can use. If you go with species only, you can set up a small canister like the ZooMed 501 or Tom Rapid Mini. Have it spray down on the gravel. Small HOB's can be made into waterfalls. This as well would provide a nice effect.