I believe that our own ThumperDart can put you together a carb that would rival the retro-fit throttle body systems in driveability and for a lot less money and hassle.

For that matter, if your cam is mild and idle not too lumpy, the new Street Demons that look similar to the old Thermoquads are very good carbs right out of the box for mild engines. And for $300 or so, are a real bargain to boot. Lots of Youtube videos on them.