I can see how you wound up at this point. I normally don't like to suggest self-contained water cooled units, but can you stuff a Corsair H70 or another self-contained liquid cooler into that case? The heatsink won't be an issue, and maybe the radiator can fit somewhere.
The reason I don't like these is because the mobo can sense when the fan doesn't work, but not when the pump fails. You're left with a tough to diagnose problem of a heat-shutdown when that happens. But if you keep that in mind, and suspect pump failure FIRST if a shutdown occurs, you can mange it.
Other than that you may be stuck with a 92mm cooler, less than optimal.
No true. I had my corsair h50 getting power from the cpu fan lead and it showed rpm even when dead and leaking water. I don't know if the pump was still drawing current or what, but my temps were in the high 90's.