Bang for buck Dayton HSU line vs. Boston XB6 others

[Kuraudo]

Right now I'm looking at research on subwoofers.
I'm looking to spend under $300 for a sub because I'd like to spend a larger portion on the newest Onkyo 805 and that already surpasses my budget by several hundred dollars. I plan on buying a new sub, Onkyo receiver and boston acoustics CR57 as rears to complete my line of Audio. The budget is $1200 for all 3 of those. I'm willing to stretch my budget to the Dayton 12" if the 10" is inadequate for my room size or if someone knows where I can get the Onkyo for $600
My budget has already been stretched by double, and I might can it all if I can't make ends meet here with living expenses.

Cr57 pair: $108
Sub: $300
Onkyo 805: $700

My bedroom is 16 feet Long, 12 feet Wide, 10 feet high (give or take half a foot on any measurement) So about 1920-2000 Cubic Feet.

I'll be using it for music movies, and games in an even ratio.
So the sub is required to be punchy and detailed but also having a decent amount of power for my room size. It has to be an upgraded of my current sub. My current sub has long lived its day and need to be upgraded.

Sub is still Klipsch PC Promedia Ultra. (dual 8" 200 Watt)
My fronts owned are Boston Acoustics CR67
Rears will be upgraded to Boston Acoustics CR57 (currently klipsch pc speakers)
Center owned is Infinity Beta C250 (because I didn't like the "matching" CR Center that Boston had with small drivers and passive radiator/fake speaker)

I intend on transferring the Klipsch Promedia Ultra setup downstairs for my Mom's TV, although it will be underpowered for the living room.

I have different speakers because I once started out from PC speakers as a poor teenager and now I'm an adult earning my own money.
However many people agree on the forums I have friends with that the Klipsch promedias and Infinity line have good timbre with the Bostons.
Its just the promedia sounds pretty harsh and compressed to my other speakers.

Subs:

Dayton HSU 10" $292
http://www.partsexpress.com/pe/showd...number=300-392
Dayton HSU 12" $389
http://www.partsexpress.com/pe/showd...number=300-394
Boston XB6 $249
http://www.amazon.com/Boston-Acousti.../dp/B000JNS3JI

OH thanks for looking