Lots of info in the Driving Cab Info thread stickied at the top of this forum.
For your situation, I'd recommend an Ultimarc U-HID
http://www.u-hid.com/home/index.php as the interface.
It supposed to work with the original arcade potentiometers, but there have been a few reports of the A-Pac (ultimarc's other analog interface) not working with 5k pots and newer versions of MAME.
So there is a possibility you'd end up haing to switch out the potentiometers for higher value ones.
If you can find connectors that plug into your current wiring, you won't have to modify anything.
The reason that I recommend the U-HID is that it's pins can be configured as outputs.
With outputs and Howard Costa's MAMEhooker software, you could have your lights and rumble motor work as they did originally.
The A-Pac is simpler to install if you aren't worried about the light and shaker motor. Those will only work in a couple games anyway.
http://www.ultimarc.com/a-pac.htmlLook in the monitor sub-forum for info on interfacing with the original monitor.
I've never done that and can't be much help.