Before making patterns, I'd finish what you started and get it on an engine and test. Use an wideband O2 and 6 EGT to monitor the distribution.
3 of these throttle bodies would be a lot simpler to make a manifold for - run a balance tube between them.
Remember that with EFI your not relying on the intake to provide a strong signal to the venturi's so going with more throttle area has minimal impact - which is off idle throttle response it "fast".
