Sub and Amp Question

I have a rockford fosgate prime r250-1 amp with a 6 inch bazooka tube, I like it but would like to have another sub. The amp is behind the driver side rear seat and the sub (bazooka tube) is behind the passenger side rear seat in a double cab. I originally went to get a rockford fosgate prime r2 10 inch shallow mount, but the installer said that the sub box that it came in would not fit. I didn't want to cut anything or remove anything, the installer said that I would have to cut the child seat hook that was back there to fit the 10in. Is there anyway that I could get the rockford fosgate prime r2 10 inch shallow mount or the rockford fosgate 10 inch punch p3 shallow mount to fit behind the passenger rear seat without cutting anything? Also would my amp work with either one of those subs? I would like to have a 12 inch rockford fosgate but I am pretty sure that I would have to cut alot and I don't know if my amp would work well with the 12.

 

Basically all I want to know is, is there any way maybe I could get my 6 in bazooka tube to sound better? Will a 10 inch rockford fosgate shallow mount fit behind the passenger side rear seat without any trimming or cutting and will my amp power the 10 with no problem? Do you think a single ten would sound good or would I need a 12?

 

Yes the either 10in will fit behind the seat without trimming, you just have to build the box around the brackets. You will have to remove the plastic storage bins behind the seats though. The amp will power either of those subs. I'm not sure what your definition of "good" sounds like so I can't answer that question, but I have a single ten and it fills the low end very well.