I've heard that the ddr-800 and c2d do not work cohesively. Any help appreciated.
Whay you mean to say is that at DDR2-800 speeds, the bus/memory ratio is not 1:1, correct? It would only cause a minor drop in performance (I don't even know if the drop would be noticable). If you buy DDR2-800 memory anyway, you can just underclock it to DDR2-533 speeds to match the bus speed.
The DDR2-800 memory is a requirement if you plan to do any serious overclocking with the Core 2 Duo.