Ok, so updates?
I have the amp, its a JL J2 250.1 and that's going to be dedicated to the sub, which is going to be a focal 25 A1, nominal power 200w, and max of 400W.
The amp was sourced locally from a friend who parted the car, the sub I ordered today from amazon, and it should be here on friday.
On thursday I should be receiving the sub enclosure by nik (ubber stealth audio)...
Also, I ordered 100 ft of 12 AWG wire to re do the entire cables, and not use the factory stuff... I also got 4AWG wire for the amp-batter) and ground connections.... Additionally I ordered a sub woffer cable (monster) and 2 monster RCA 25' cables for the conections between the head unit and the amp (speakers).
Well... Looks like tomorrow I'll be wrapping the exhaust in thermal wrap, and I'll do an oil change and tire rotation... And on thursday or friday I'll be re-doing all the wires of the sound system, and I'll install the sub+amp.
Let's hope for a good week.