There is more control and better power from the Weber-Alpha hybrid design.
(There is a reason converting to fuel injection on hot rods is so populaur.)
I do agree that the novelty factor of going straight carb is cool, and can even offer more power than our current fuel injection setup.
As far as where to put the filters for a carb setup;
Simply cut into the firewall and use the area under the windshield cowl as a large intake plenum.
Half the cowl grill (big plastic piece that has the wiper arms sticking through) is a solid piece (and it just so happens its the side where the carbs would come through the firewall) and the other half of the cowl grille has air solts in it, so all you would need to do is add a filter to the underside. Talk about a cold air intake.