I also wanted to say it would probably be cheaper to go to the junkyard and find a car that might have everything you need and take it with you including the switches, *****, gauge assemblies, sockets, fuse box, fuses relays and start from there then hack off what you don't need.

get the wire harness from a car you know will be around another 10 years and can get parts for and are plentiful from a junkyard from say a honda civic/accord.