[blykins]

If you can get them to seal up, Dove makes some heads that supposedly flow 400cfm.

Also, Blue Thunder is making some heads right now that show about 360cfm on the intake side (someone posted a flow sheet on the FE Forum a couple days back).

Of course if money is no object, cammer heads would probably be your best bet.

As for the Weber setup, I've never seen or used a set, but I've heard the name Inglese thrown around a couple times.