Leaving static weight distribution out for the moment, what wheelbase would be better for a 1,000 hp street car:
1. short (A body etc. 108" or less) for maximum weight transfer and slightly less overall weight
2. long (B body etc. 116" or more) for stability at speed?

To me wheelbase needs very little. Assuming no flex, the chassis only knows C/G vs instant center. Short wheelbase needs more front weight percentage. Front wheels are just along for the ride. Plenty of fast Fox Mustangs at 100". Besides a 1000 hp street car will be steered by the rear tires and throttle.
Doug

I know you said leave weight distribution out for the moment, but it is a big part of the input I can offer.
I think a 100 to 108 inch chassis would work well, allowing good weight transfer.
Since traction will be very poor, rear weight percentage becomes VERY important. As an example, going from 50 / 50 distribution in my 106" WB Dart to 53 percent on the front, there was a serious loss of acceleration on my "test" driveway If I were ever to build a 1,000 hp street car, I would use a similar chassis, and get the rear percentage of weight as high as I could, hopefully as high as 60 percent or more, with a Cg higher than what would be found on a chassis that works well at the track. As a safety measure, I might equip the car with some rather short (not sticking out from under the car) wheelie bars, just for safeties sake.