Finally we have reached the penultimate update of the silent Lian Li! I got my Arctic Cooling S1 Plus heatsink at last and installed it a few nights ago. I thought their G1 thermal adhesive was going to be hard to work with as after I applied pressure and let go, the VRM sinks slid around, but luckily after curing for a few hours they didn't fall off and I was able to mount the actual VGA sink. First off, it's BIG, but not ginormously so, thus most cases will be able to swallow it. Secondly you really do have to check the heights of any capacitors on the board itself, as it JUST clears the tops of the capacitors on my MSI 7770:
View from the front intakes, relatively unimpeded, straight to the two passive sinks. I may build a duct for the bottom fan to channel air directly to the GPU and out the exhaust, but temps look fine at the moment, we'll see.
I used MSI's Kombustor to stress the GPU for an hour, and as you can see the max temps reported by Afterburner (and Hardware Monitor) was around 75C (it plateaued there and wouldn't go higher, and in fact started to drop).
View from bottom intake.
View from top intake.
I had some braided wire left over from suspending my Ninja and used it to brace the GPU sink as well. Instead of drooping down, it hangs perfectly parallel.