check out my install from 2 weeks ago,
I went around my a$$ to get to my elbow installing, lol, but I have dual 10" sub enclosure under rear seat, sub amp under passenger seat, and 4 channel amp under driver seat.
I have 0 gauge branching off Distribution block to dual 4 gauge running to each amp.
I installed 4 JL Audio 6x9 in doors, and have to say, after I resolved a PAC controller issue, and figured out my dash speakers (factory) were causing issues, the system sounds pretty damn good. Im going to be adding a Kenetic Battery under rear seat however. I no longer have the severe lights dimming, and voltage drops however I can tell that the amps are feeling a little deprived of power when I am driving at night, using wipers and heat or AC.
As far as labor goes, I took front seats and console out cause this was my first solo install and I wanted to make sure I was able to hide all cables.
I need to get in and take some more pics, but aside from the RF Bass Knob being installed and recessed inside the dash change pocket, everything is as stealth as possible. The knob can only be seen if you are sitting inside truck as well.
In order to just install amp and dual subs, you will not have to remove the seats, just pull the head unit and install line out converter, run RCAs and turn on lead, run power from Battery to amp. Carpet lifts in many locations enough to tuck and hide all cables, you can run speaker wire under carpet into the under-seat location, and install you Sub Enclosure.
Good luck, and dont forget pics...