I'm a n00b too, but I'll try to help lol. Anyway, for the switch thing, I know some BIOSes have an option to automatically "turn on after power loss". So pretty much, when you plug it in, it boots up. Snoop around in your BIOS settings to see if you can find it, maybe look in the manual. But nothing is ever that easy, so we need a backup plan. I wonder if there is some type of relay that would send a momentary signal (most keep sending the 12V through, we need one that would send it for a split second).
For the inexpensive deck, check out the Alpine CDM-9821, $139.99 http://www.crutchfield.com/S-FPetPMe...rch=CDM%2D9821
It has one pair of pre-outs, and for the aux input, you need the Alpine KCM-122B, $14.99 http://www.crutchfield.com/S-FPetPMe...rch=kCM%2D122B
I think all of the Alpine head units have the Aux-in thing with that adapter, so whichever one you choose should be fine. Good luck and take some pics of the setup if you get a chance!