Is a 650 carb what I want?

For the street, a 650 would be excellent to use. The difference between the two carbs is probably only 10 HP or so at best.
4spd cars enjoy a double pumper more so than a automatic car does . It is possible to use a DP. The issue concerning the use of a DP vs a VC carb is timing of the secondary opening. With a DP, all the control is in your foot as to when the engine can use all the barrels open, or not.
The VC carb will it for you. You can tune the carbs secondary side a bit with different parts from Holley.
If it an AFB carb, tuning the secondary side is mostly out. Possible, but a huge pain if it needs
To be delayed.
If it is a AVS style carb, the air door is tuneable with a screwdriver for quicker or slower rates.

Considering the partslistes, I myself would go with a 650 AVS.