Those solutions still don't seem to solve the problem of not having enough space for the fans to get any air to them.
I was thinking about going with something like the Thermalright HR-03 GT
which can be mounted two ways. One where the fins will loop over the back of the top card towards the CPU and then strap a fan onto that. That will give the fan enough air-room to cool it (I think, this should work) And to cool the VRM and memory I'd go with Enzotech MOS-C1 heatsinks
and Enzotech DMR-C1 heatsinks
Or, my other choice is to go with a $500 watercooling system, if I went this route, I'd also include the CPU in the loop with the 2x GPUs.