Like someone else mentioned, the SQ10 seems perfect.

Model Name : SQ10 Subwoofer
Available Voice Coils : Single 2 - or - Single 4
Power Handling : 250/500 WRms
Vented ( ideal ) 1.0cF Tuned to 30Hz

 

KFC-W2510
Not the prettyest sub but seems to be within your criteria.
Rated Input Power . . . . . . . . . . . . . . 175 W
Sensitivity . . . . . . . . . . . . . . . . . . . . . .91 dB
Voice coil . . . . . . . . . . . . . . . . . . . . . .4 Ohm
Frequency response . . . . . . . . . . . . . .28 ~ 800 Hz

Needs little power and is very efficient plus recommended ported enclosure is 1 cubic foot.

I think this model will be discontinued so you might be able to get some good deals on it.

The 12inch version is also a good choise, 1cubic foot sealed recommendation.
KFC-W3010
Rated Input Power . . . . . . . . . . . . . 200 W
Sensitivity . . . . . . . . . . . . . . . . . . . . 93 dB
Voice coil . . . . . . . . . . . . . . . . . . . . 4 Ohm
Frequency response . . . . . . . . . . . . .25 ~ 800 Hz

 

The Orion C2 series would work good for you. Check out their specs on ORIONCARAUDIO

 

Out of all the ones mentioned I second the Orion C2 series sub. Lot of bang for the buck.

 

According to WinISD the frequency response curve of the Orion C2 12" in a 1 cu. ft. box is virtually identical to the PG I have now, except that it's about 3db quieter. My quest may be all for naught!!

 

I think I'm just going to try stuffing the box with 2lbs of batting, dropping the bass by about 3db to get rid of the 100hz hump, and boost the sub-channel to extend the bottom-end punch a bit. Hopefully that'll make me happy . .. . for now.

 

It never hurts to try tweaking equipment!

 

I remember hearing something about the install making all the difference, but I could be wrong

 

Hey Ffej1960, are you on 306motorclub?

 

Uh, no . .. never heard of it.