I first thought since I didn't have all the power options like air conditioning, Power windows, Power locks or a modern drive line the ISIS would be over kill but after researching it more and thinking about all the electronics I will have like Electric Fuel pump, dual cooling fans, LED lights, push button start, upgraded ignition, electric water pump and then all the options that ISIS offers for those functions like soft start fans, delayed headlights, engine fan cool down..I think it might be the way to go.
First off, I love this build thread! What I like most of all is that you are saving a car that might have otherwise been parted out.
For our Scrapyard Six project we are strongly considering ISIS as it will allow some nice control and easier expandability of our car down the road. Dan Martinez from ISIS has been very informative and the ISIS architecture is robust. You don't absolutely need it but if you want to do electric locks, trunk, door poppers, any of that I'd say do the ISIS as it will be easier and lighter. We are swapping EFI though so that's a whole other harness. To minimize over current requirements we are going with TruckLite LED headlights, (I give these an A+), but they are a bit pricey. Our Supra engine has a pretty strong Denso alternator so I'm not too worried here.
Drop me a PM if you are leaning towards it and I can give you a better idea on how we'd like to deploy it.