Thanks for all of your insights.
I've used a PCV valve and breather in the other cover in every car I've built with no problems. That included my 1941 Willys coupe with a Chevy 502, tunnel ram and dual 4 barrel carbs and my Factory Five Daytona Coupe with stack EFI. My dual carbed engine for the GT40 has a 3/8" nipple in each carb spacer for a PCV that I could gang together and run to a PCV, venting the other cover. To Scott's point, I could simply run two breathers, but my valve covers are not baffled and there is not enough room under them for a baffle without valve train interference. Hence, I didn't think that either of these two options would work effectively.
The bigger issue I am grappling with is suction or no suction to be blunt. I like Randy's idea of two lines to a tank with a vent on the top and petcock on the bottom. Simple and effective. I am, however, intrigued by Richard, Frank, and Keith and their experiences using vacuum to aid in evacuation.
So, to suck or not to suck. Gentlemen, that is the question!