No. 800 is the correct speed in this case. Only a few boards support faster ram and the cpu must be overclocked for it to run at the faster speed. It's much cheaper to switch to a ddr3 775 board to run faster ram than buying 1066 ddr2. I would sell your board (it should bring a good price) and switch to 1155 if you're not happy with your ram performance. Only Intel has 4 slot ddr3 boards and those boards won't overclock well. I found my used 2120 cpu/heatsink/asus h61 board for $125 on craigslist and 8 gb of ddr3 is less than half the price of ddr2.
When I overclock the cpu, I let the motherboard select the ram speed. That's all I can tell you. I prefer stability and you sound like you can't afford to upgrade or replace faulty components. Don't get too greedy with your overclock. The frame rates aren't that much higher with extreme settings. And if your windows installation crashes, be prepared to do a fresh install.