I would have probably been able to take it further with another 8800GTX but a "budget" PSU blew the living crap out of my SLI connector and one of my 8800GTS 320MB cards...
LOL!!!! You just answered a question I was about to start a thread for. I have to choose between my 800W BFG and a Coolermaster 1000W (Got it for free) to keep for my system. I know I will probably never come close to 1000W, but seeing this made my choice for me.
Remember, even at 80% efficiency 1043W means that the ACTUAL load on the system is a little over 800W. On a 1200W PSU like the one I was running, this king of load is just fine but this would be pushing it for a 1000W unit if it was the load you were putting on your PSU on a daily basis.