The reason I asked about this is because I had basically the same idea - I asked about a HS like this in the HS area, but no one knew of one
It was either this or another solid block design I came up with.
I figured I'd have the barbs enter into a chamber that would feed into the fins. I'd put a knife edge on the ends of the fins to lessen restriction.
In my opinion, the pic with the fins on the sides cut off should work good for a block sitting on the CPU. I think you could use more/all of the fins if you were going to go with a Pelt setup.