No idea really where to start....just interested and willing to do a lot of work. The only thing is, I would like to be able to switch it back and forth....(even if it takes a long time to swap)
So, where do I start?

could I use this somehow? Or get a used CP from the racing games I am actually looking to play and use their parts? Just about everything in my cab is hooked up with a molex plug, So I could make some type of harness if needed.

I could make a new metal CP that would house the components and fit on my current cab. I also have a base for my cabinet that could easily be used to hookup the pedals. I would want it to be a stand up one player racing game...or maybe sit with the pedals in an external case. Play it with the door off so the wires could run in.
Design isn't really the problem, but more of what do I need and how do I wire it in?I am looking to play games like Sega Rally 2 and Daytona USA 2.....or even initial d. So I am not sure what type of shifter/pedals I would need....
Here's my cabinet:

Here it is with the stand up extension on it that I could mod for the pedals:

Well, what do you think? I guess it would be trying to be setup like a crazy taxi game...

any help would be appreciated!!!