Stock '69 318, t-quad vs q-jet vs holley vs edelbrock?

I'm thinking of doing exactly what you suggest if I can get a friend to help me with the TQ tuning/rebuild process. I think I'll get the Doug's headers eventually but if I can stick to stock manifolds for the moment that would be a lot easier on the wallet.
Do the intake and carb first and learn to tune the carb. When adding headers and a more free flowing exhaust you will likley need to tune the carb some again and you'll be more confident in doing so.

Is your car an auto or manual? Power or Manual steering?

Don't overlook 340 manifolds as well along with suspension and brake upgrades.