I'm new and never done a full out AV system. I'm confident in performing the tasks at hand and would like suggestions on building a ridiculous av system.

This is what i want

GPS
DVD
Back up camera (cant see when backing up at all)
MP3 player
basically a windows based program so that its near a PC.

This is a lot of stuff and i might need to do one thing at a time.
but know i can do this somewhat affordable.
I can build a mobil pc from newegg.

there is much conversation on screens and such but would like to really go hightec without high price. Thats what everyone is after right?