With the engine configuration you list, you are better keeping a Quadrajet on the engine. A QJ is a better carb for your engine, especially the driveability. Edelbrock makes a good Quadrajet clone. That said, it's clear your QJ experience has been "dirtied" perhaps by poor-quality rebuilt carbs. A 650 Holley would be a good choice, but don't believe that a Holley is any easer to tune than a Quadrajet...well...it depends on what "tuning" means to you. In fact, a Quadrajet is more "tunable" than is a Holley because it uses metering rods. On the other hand, Holleys are a little easier if "tuning" means just changing jets.
Good luck and Merry Christmas.
Don't be surprised if your bog at fill throttle remains.
If it is still there when you're done with the Holley swap, start troubleshooting your fuel supply system. Inspect for restricted fuel lines. Pull the sender and check the "sock". Change the fuel filter. Test the fuel pump and replace if necessary.
Also, what your spark timing is doing may affect how the engine runs at WOT. You may want to make sure the distributor advance is working right and that the timing is set properly.
