It sounds a lot like what we've been discussing in my "Ultimate Waterblock? Theory" thread.
I'm fixing to have a prototype made (with a little help from my friends
) of my design#2. I haven't ironed out the details yet, but it'll also have a radial pattern of fins, over the core.
It seems like the best option for structural integrity (given a very thin baseplate) would be to start going around the sides of the core, and/or like Cathar, have fins to reinforce the structure.
I'm getting excited about this project...