Here is my current setup in my 69 Camaro.
468
Rectangluar heads 2.25 /1.88 valves (I dont intend to change them to oval for several years, money issue)
10.5 to 1 KB forged pistons,
Full hydralic roller setup
Edelbrock Airgap RPM manifold
Hooker super comp headers.
4 speed
4.11 gears.

The Camaro feels very sluggish at lower RPMs with the 850 HOlley double pumper. I am thinkinng of getting the Street Avenger, either the 770 or 870 and not sure if I should AND which one of the two to get. I am interested in picking up more low end power and acceleration, but do not want to loose top end horse power. I do take it to the track, but rarely do and am interested in more power on the street. So, so should I just keep the 850 or get a street avenger and which one.

I think the carb has very little to do with low rpm sluggishness. It's usually a function of cam duration, timing, intake velocity and exhaust physics.

Well, you didn't give any specifics on cam profile or tire height, those would be useful. That motor is gonna be slighty lazy at low rpm with those big valve big port heads. If it's particularly sluggish though, I'd look to carb/ignition tuning before blaming the carb. Because that 850 DP should run like a raped ape on that motor. Depending on cam and tire, you may need a bit more gear.