A bit in the weeds here but here it goes.
My build incorporates a 360 and PC in there. The PC talks to the 360 via an arduino for polling power status and turning it on and off, and FTP to launch games. The arduino also turns on a relay to swap all of the input microswitches to 360 controllers, but that took a forever to wire up and too many relays to count. For the wheel, I used a fanatec gt2. The wheel used wireless comm to connect to a 360 but USB to connect to the PC, so no manual wire switching was needed. To swap modes there, the wheel needs the back button or Xbox buttons held on reboot...so when switching platforms from PC -> 360 or vice versa, an arduino sent a power off signal to a PowerTail II switch (basically a relay-controlled power plug) to reboot the wheel. I then opened up the wheel and soldered extra wires to the Xbox button (easy) and back button (massive pain in the ass as it had to go through the steering column and was a tight fit). I also put the arduino in charge of checking if the 360 turns off and if it does, restore the wheel to PC mode.
For video input switching, I used an HDMI switcher with an RS-232 port, which lets you send switching commands to it over a serial port (I used a USB-> serial adapter). My front-end was aware of if it needed to swap out the controls and video etc so just communicated w/the helper programs I wrote for that.
I should note the 360 was modded and set up to run an ftp server on boot that allowed for exec commands.
I haven't really put up much info on the driving "extension" of the cab, but the upright has a bunch of info in my thread for it.
Was a ton of work for all of that. Am I happy I did it? Absolutely - because I learned a bunch and its neat having everything be automatic. Would I do it again? Probably not; there are many more opportunities for failure with a more complex setup.
I know you've already ordered some stuff but if you or anyone else ever wants to try anything remotely similar, feel free to hit me up.