Gee, you didn't mention you didn't have baffles.
Why don't you just get someone to cut some slots in the tank and slide in some baffles and weld.
With some baffles you could just use any pump. We know the VL pump has the capacity and is cheap.
The only time you will have problems is hard acceleration/corning when tank is low. Keep the tank full for all competition work and you will be fine. This is what we did we have old DRB Cobra. Once we got down to 1/4, that's when we started to have problems.
Personally the best solution is to use a low pressure lift pump, to an external surge tank and then high pressure EFI pump after that. But don't worry about fitting that initially, wait to after the car is finished and see if you need it. Less is sometimes better.