Annular vs downleg boosters on carb

Considering a new carb. AED
The place i am looking at doing one can give me the “ look” i want( black carb, red boosters and metering blocks.
I figured on a 950.
They recommend an 850 with annular boosters. I know an 850 is generally “ bigger” than a 950. He said the 850 if he uses annular boosters will give me the signal i want.