Best pre-owned subs below $1k?


It's about time I finally add a sub to my system, which I've been piece-mealing together. I'm a big believer in taking advantage of audiophile nervosa and grabbing a bargain on the pre-owned market.

As far as what I'm looking for, if there is such a thing, is the sub-woofer that provides the least (read idiot-proof) placement challenges. I should add this will be for an HT-only rig -- I have a dedicated 2-channel system in my living room.

The room itself is not a large one, say ~20' wide and ~11' deep. Because of varying reasons, my viewing position must be in the center of the backwall of this 20' wide room, placing me about ~10' from the system. My processor will be upgraded later (it's just an older Fosgate pro-logic processor right now), but my amplification consists of a 200w x 3 B&K amp for the front three channels, and a 200w x 2 B&K amp for the rears, all driving NHT VS-2s.

All that said, are there any no-brainer choices on the pre-owned market between $500 and $1,000? And, among those, are some less room/placement dependent than others?

Thanks in advance!
kitchener
An added question, given the above -- would a pair suit better (a couple of Sunfire Jrs or something)?
I paid $1100 for a used pair of Velodyne ULD-12 powered subs a few years ago. These work so very well in a Home Theatre application. Having two of these allows for better bass balance around the room. My only complaint is that they are walnut which does not match well with the maple speakers in the room but it's often tough to have it all. At least they look more like end tables as they are down firing.
I have an HSU Reseach 12v down-firing sub that looks like a table aswell, but it is my opinion that in your case a front firing sub may be easier to place, like in a corner "toe-in" a bit....or a few feet in front of speakers on side of room again toed in a bit, down firing subs are more tricky because the sound fires down and spreads out, making walls more fussy with ideal bass response...good luck and have some fun with tweaking the placement! Chad