How's it going? since you have been involved with pc's and some electronics since you were knee high to a grasshopper, you have a distinct advantage.
I tell new guys that i did a LOT of reading and searching these forum posts for abt three mos before beginning to buy eqpt. See my specs and pictures - see other's specs and pictures for some good ideas and inspirations...
I kept it simple with an inverter and desktop pc. I've got lots of room in cargo cmpt of my wagon. There WERE a couple of inverter noise issues, but re-routing cabling and a couple of other fixes cured it all.
The in-dash screen DOES sound better and better. If you have a double DIN opening for stock Hu, that makes things easier. I figure if I disassemble my Lilliput 7" touchscreen monitor (was $245 mp3 car store), it will probably fit perfectly where stock stereo was. Of course, buttons from monitor would maybe need to be relocated, but that's all not really hard. Just takes some planning, and look at what other guys have done.
This carpc thing is a lot of fun, and the guys here are suprisingly friendly and helpful (you may have observed how knowledgeable electron geeks can sometimes be a bit ****y...) This is definitely a community.
Lookin' fwd to hearing from you.