Hmm, you'd probably have to ask Edelbrock, Holley, TPIS, etc. More than the plenum size, I think it's the runner length that decides one of the characteristics of the engine.
I've seen the single plane style you're talking about, basically a carb manifold plumbed for EFI right? I've seen those things make plenty horsepower with the right cam and exhaust, etc. However, I went with a TPIS MiniRam2, mainly for hood clearance, possible future forced induction, and simply the looks.
If you find an answer, let me know.
Owen