Welcome to the nutthouse

As far as gauges I would look into Fsxpand, Its inexpensive plus you can customize the layout for such a unique deck. Of course FSUIPC from Peter Dowson is a must. your gonna need to get some monitors for your avionics, I did some ebay and I currently have 4 12.1" monitors for cheap. Your gonna need multiple PC's for the elements. All Electronics will help with switches, wire, connectors etc etc. JBaymore swears by Hagstrom cards for interfacing hardware.
The list goes on and on, not to plug my site but I have a few links in the Hardware and Software sections that could help:
http://homebuilt-cockpit.masternerd.comSounds likeit would be a cool pit! Good Luck
John