The professional products airgap makes 25 less hp on the dyno than the actual edelbrock. Tested it myself. I haven't done anything with a thermoquad besides replace them with holleys. Not saying you can't make them work, just not my preference. Also if you don't have, or don't know what an anti ballooning plate is, your converter isn't long for this world on nitrous. I'm just going from my experience and years of drag racing. What you are describing isn't a low 11 second car. It may be an awesome ride, and will put together. Not knocking it. But on paper....the numbers are what they are.
