I don't know what your budget is but it seems that with an intake and carb and Efi swap you're getting ready to drop some serious money. If it were mi e I'd use what you currently have and go to a good Efi system first. No it is not optimal but I don't know how much having optimal versus still pretty damn good is worth to you. Your heads are big but they can work just fine on a street engine, not optimal but still just fine.
None of the suggestions have been bad ideas but they're not cheap either.