Dabbling

I have a 55 gallon aquarium 48"x18"x13". I have 6 (2" adolescent, expected to reach 2.75" at adulthood) bengal loaches and 2 (2" adult) dwarf clown plecos in it and I would like something else to go in there with them. I'm looking for something that will not cause much trouble. I was considering a school of glass catfish or hatchetfish since they both seem to do well with some current in the water and they both stay towards the top.

I wouldn't mind checking out some other peaceful community fish before rendering a decision. I would ideally like something with a light body color. I have black sand as the substrate and gray virginia slate and malaysian driftwood as the decorations / caves. I also have a good set of moon lights built into my Current USA Sattelite lighting rig, so the idea of light colored stuff that will show up in the moonlight entertains me.

Thanks for any suggestions or ideas.