Absolutely! Very easy to do. The switches will be grounded rather than having 12volts run to it. The normal "power" wire will be run to ground, then the opposing positive is run to the mastercell. Cake walk, done & done. For gauges, the only difference is where the power comes from. Signal for gauges is still from their traditional source. ISIS also offers a kit to simplify wiring gauges, though I personally don't think it's all that necessary.
If you can get away from the price disparity, in my opinion, ISIS really does revolutionize wiring of cars, particularly old cars. On pro-touring.com, the discussion of cost has come up and ISIS came on saying to connect with them when ready and they'll be sure to take care of us. I can vouch for that since I just purchased the remaining components of my system. Contact Jay Harris there and tell him I sent you. I don't know if it will get you very far but I set up the first group buy with them and we sold almost 50 units and they've been great to the guys on pt.com. A great group of car guys at ISIS who provide incredible service for their product. Never hurts to contact them.