Joel, Plan A of recessed bellmouths and low profile plenum is the simplest and best option I reckon. All these long runner will cost you alot of top end and most likely bottom end if you go FI. All of my shorter runner versions of the UZ manifold made more power everywhere with the shortest runner manifold giving the best result.

That's more low end as well !!.....which goes against the rule of thumb conventional wisdom, but for FI pipe diameter appears to be at least as important for making torque as runner length.

All the manifolds you are looking at are designed for optimising boring road going low end torque. I'd bet that the short runner design will be near enough in low end torque and worlds ahead for mid and top end. Having a much lighter car works in your favour as well. Keep it simple mate