jl's are really good, especially if it's gonna be your first system.. inside the cab, it will sound very nice. outside, like a few have mentioned, it won't be as loud, obviously (but who cares about the outside, you'll be inside when its playing). do you know what size w0's they are?? i got my first system when i was 15, it was 2 12w0's, powered by an older kenwood amp, they sounded great in my p.o.s. mitsubishi montero (the inside of that thing wasn't too much bigger than our ext. cabs, picture almost the size of a jeep maybe) anyhow, they'll sound good within, and you shouldnt have too much rattling at all from them.
2004 Ford F150 FX4
Mods are here and there...