For the PSU good options for you are the Opus120 (120W) and M2-ATX (160W). The via boards draw soooo little power, that really anything will power them.
And
about the screen. VGA and USB are your friend. If you buy on eBay, make sure you see those. Sometimes they will sell RCA only screens with USB or just VGA screens, no touchscreen! So watch out.
Software, well RR is awesome it is my favourite and the install wizard makes config hassles a thing of the past pretty much. You will also need Winamp v2.95 for RR to work. Probably get on IE and go to some flash site, and install the flash plugin if you dont have it already. And even though IE = evil, it is the easiest way to get the plugin installed.
Also you drive a BMW. I am not up to spec with BMW's, but I believe you are one of the lucky few who could benefit from the I-bus thing. I dont know if your car is new enough, but definately look into it.
And for reverse cam, make sure to get a nice wide angle lens. And you could get a standalone one (like off ebay or something) and get a Xenarc screen that automatically switches to the RCA connection when a signal is received. More OEM that way.
Linear Mode
