Best "small" sub for Joseph Audio Rm7 speakers

Just purchased some new Joseph Audio Rm7 speakers and want to add a subwoofer. Intererested in a small sub and this will be used to listen to music only. Heard inconsistent things about Sunfires and don't know about whether a Rel Q series or small M & K would be best. Any suggestions?
Check out the ACI Force. An excellent subwoofer, small and musical, works well with my Spendor s3/5.
The RAL Strata III is fairly small and very nice looking in a wood finish. Damn fine sounding and easy to integrate sub too.

I would highly recommend that you check out the Velodyne DD-10. Put away any preconceptions of what you think Velo's sound like. This baby is musical to the nth degree. I have a DD-12 paired up with my Thiel CS3.6's, and it continues to amaze me.
Do any of these subs have volume remote control capability
or any other great subs for that matter. Im also looking to put a small sub in my system.
Velodyne DD series have remote control volume, night mode (adjustable attenuation when the kiddies are asleep), multiple presets for different types of music/HT, etc.
The velodyne SPL 1000.