The two barrel is the way to go, and WILL give you a giant step forward
from the pea shooter, finding a small 4barrel gets expensive and sometimes don't do as well as a 2 barrel , Pettybludart is correct and yes the four barrel systems will run you well over $500.
I got lucky, a Mopar friend here in town sold my old offy 4 back to me for 100 and my wife and children payed $345 for my carb 390 Holley DB.
If I was to do it again it would be a super 6 system.