The RF amp will not being able to push 2 15L7's to what you want them to be at. With the new L7's, I think they have an RMS handling around 1200 watts, so the most yoour amp could do would be 1 15. BUT, you could do the L5's.

Again, if you go this route, I'd definitely look into getting a class D amp - something along the lines of a DEI 1100d or Memphis ST1000d (one per sub). These amps are smaller in size compared to an 800.2 and will also drain less juice.

As for the sound outside of the car, the square Kickers can definitely do the job. The bass is very deep and hits very hard.

I'm pretty sure my friends old set up in his 92 Integra hatch with a single 15L7 and Memphis ST1000d was in the low 150 db range. My 15 was in a smaller ported box and in a less-db friendly car and I hit 144 db's.