[demick]

Alpine PDX5 is one of the few 5 channel amps that will fit in the stock location, and is a very good choice. I assume you will replace the door and dash speakers in the process, as well as the head unit. The last remaining item is the sub. Some have done them behind the seats, or in the passenger footwell. The other option is to buy the Bose subwoofer that goes over the engine hatch as was pointed out by the previous poster. Not a lot of room in any of those locations. There is poster over on Renntech that makes a subwoofer box for the stock Bose sub location. Looks very nice, but is is $$$ if I remember correctly.