If it is just the wiring part you need help with you might be able to ask for help on some 3000gt forums too. If somebody is good with installing an amp, they can install a PC. Power, Ground ignition, fuses, and then just a few extra cable run up to the dash like vga, usb and such.
Just making sure you get a good response, might want to ask multiple places. Maybe you already did, I dunno.
I'm in CO, and I don't even know what state is abbreviated by MA but I am guessing maine, so I can't help. Good luck though.