@theJman: this is a good list; I'll check them out. Which one did you end up buying and what do you think of it?
Well, um, I went with something else entirely...

I started a thread over on avsforum that explains it a little better, but I'm dissallowed from including links until I reach 5 posts.

The short version though is I ultimately bought an XTZ 99 W10.16. Never heard of XTZ? Probably 99% of people in NA haven't. Their Swedish website is at
wwwdotxtzdotse/uk. The American website is
wwwdotxtzsounddotcom, but it's not fully operational yet. As soon as I can post an actual link I'll update this with mine from avsforum.
When searching for small subwoofers what I basically found was the size of a subwoofer was inversely proportional to it's cost, at least in the case of virtually every one of the units I listed. Essentially what that means is the smaller the sub the higher the price - miniaturization came at a greater cost then I had originally anticipated, so I decided to go in a slightly different route. I also opted to change my search to HT equipment instead, but that's a different story altogether.
Some of those subs -- like AudioEngine or the DefTech's -- are pretty reasonably priced for what you get. Others -- like Velodyne and Cambridge Audio -- are less of a bargain, but still doable. But then you get to Earthquake, Pinnacle and Sunfire and you think "really?", because they're a whole lot of money for what you get.
I guess the bottom line is size matters for several things

, subwoofers among them. And in this case smaller presents some unique/costly challenges it seems.