Need a 10" subwoofer

Is there a reason you're limiting yourself to a 10"

In a room that size you're going to want as big a sub as you can get.

Moving on, in that price range, if you're insisting on a 10", i would look heavily at:

eD A3-250, 10" Ported, 300w, $450 shipped:
http://www.edesignaudio.com/product_...roducts_id=951

Hsu VTF-1, 10" Ported, 200w: ~$425 shipped:
http://www.hsuresearch.com/products/vtf-1.html

For $550 you can get an outlaw Lfm 1-plus with a wireless adapter. Then sell the wireless adapter and have a sub which can work in your room.

Well you have a lot of options at / around that price range.

If you can stretch up a bit, that Outlaw LFM-1+ is a good sub for that sale price:
http://www.outlawaudio.com/products/lfm1plus.html

eD A2-300 if you wanna save a bit of money:
http://www.edesignaudio.com/product_...roducts_id=407

The lava Sub 12" has been getting a lot of rave reviews and its on the lower end of your price scale:
http://www.lavasubs.com/12_inch/powe...subwoofer.html

If it were me and my money, knowing what i know now, i would try to stretch up a hair and get that Outlaw LFM-1 Plus. You're really not gonna get a much better sub than that at that price.

id just go with butt kickers,because that room does need a lot of air, and i'm pretty sure a 10" sub will have to work harder.