Need a upgrade from RF p2's for better low bass
 

I apologize if this is a typical newb question but hell I'm still learning..
Now, before you all bash me for using p2's, my good friend in my unit sold them to me for 80$ because he's getting out of the army in a month or two. Not a bad deal.

They don't hit lows that well. Mid range sounds great but the lows sound empty. probably because of their frequency range. (tell me if I'm wrong, I'm still learning) Now for all the details.
I have a Hifonics 1200 watt. 1200 watts at 1 ohm. I have a ported box. 3.23 cubic feet. Separate chambers with each sub getting 1.615 cubic feet of airspace. the box is tuned to 33 hz. Only downside is this box was made with 5/8 MDF instead of 3/4. I know its a rather small box but I have limited trunk space.

Mechman 240 amp alternator and a kinetic 1800 so the amp is getting all the power it needs. Low pass is set around 70-80 (you know hifonics the just use little tick marks so its almost a guessing game) subsonic set at around 20.

This is a ridiculous question but are there subs that work well in smaller ported boxes that take about 600 watts?

Sound Ordnance™ Bass Bunker Ported dual 12" subwoofer enclosure (Model BB122-175V) at Crutchfield.com