I would have to disagree... I say ff1 is the best. Great gameplay and wasn't so difficult that it required a walkthrough to aquire everything. 7 is ridiculously awesome though.
Anyways, sorry I couldn't give any useful advice on the build. As much as I am in to tech stuff, a carputer didn't even occur to me until yesterday when I saw a link to Mp3car.com on xda. So now I'm all ready to start a build of my own :-)