the 7 inch lilliput will work out nicely in your radio spot.
I used a pro gin USB gps reciever. It worked well i had it on the dash on the back deck and mangnt mounted to the rear deck. . .worked well. . . . in all places.
i used delorme street atlas 2006
I reinstalled this setup into my 93 s 10 truck. and it came out allot nicer. i actually integrated the screen into the dash instead of just mounting it ont he dash like I did in My PAsssssat.
mini motherboard mounted to a thin panel of wood mounted in the cargo box would work well.
I just opted for a inverter for my setup.
750 watt black and decker. from walmart.
never had a reboot problem.
when i was using a lappy. I just told it to shut off when battery power got to 95 percent. so i could just shut the car off, walk away in a few minutes. the lappys weak battery would trigger a shut down.
good luck with the build and post up some pics.
i sold my getup on ebay for like 500 bux. . it was fun but i used it less and less each day. . People did like watching movies on trips.
and what not. .
The Other Chris...