For a small sub, I'm now pretty strongly leaning toward trying out the AV123 Rocket UFW-10. Some of what I've read is a general feeling that if you have to, or want to go small on a sub design, that a Sealed sub has better effect and be better musically than a ported would of the same small dimensions.

Another option that I've considered is the Partsexpress Titanic 10" model.