My system is as follows; Cooler Master Stacker 830 Evo case, Q9450, dual 3870's in CF, 4 hard drives in dual RAID, 8 120mm LED fans, blu-ray player, dvd burner, media card reader with floppy, RAID controller card, 4GB (2x2) DDR2 1066 RAM, gigabyte x38, HT Omega Claro Plus+ sound card, Logitech webcam, Thermalright Ultra-120 Extreme CPU heatsink, front panel LCD fan controller, 2 external hard drives, keyboard, mouse, 28" lcd monitor and 42" lcd hdtv. The following is the list of PSU's that I have narrowed it down to. 1) SeaSonic M12 SS-700HM ATX12V / EPS12V 700W Power Supply 100 - 240 V UL, CE, CB, TUV, FCC - Retail - $180 http://www.newegg.com/product/product.aspx?item=N82E16817151031 2) Thermaltake W0116RU 750W Complies with ATX 12V 2.2 & EPS 12V version Power Supply 100 - 240 V CE, CB, TUV, FCC, UL, CUL, and BSMI certified - Retail - $190 http://www.newegg.com/product/product.aspx?item=N82E16817153038 3) Thermaltake W0106RU 700W Complies with ATX 12V 2.2 & EPS 12V version Power Supply 100 - 240 V CE, CB, TUV, FCC, UL, CUL, and BSMI certified - Retail - $160 http://www.newegg.com/product/product.aspx?item=N82E16817153039 4) SILVERSTONE DA700 700W ATX 12V 2.2 & EPS 12V Power Supply 100 - 240 V - Retail - $177 http://www.newegg.com/product/product.aspx?item=N82E16817256035 5) SILVERSTONE DA800 800W ATX 12V 2.2 & EPS 12V Power Supply 100 - 240 V - Retail - $217 http://www.newegg.com/product/product.aspx?item=N82E16817256036 6) PC Power & Cooling S75QB 750W EPS12V Power Supply 100 - 240 V UL, ULC, CE, CB, RoHS - Retail - $150 http://www.newegg.com/product/product.aspx?item=N82E16817703009 7) PC Power & Cooling PPCT860 860W ATX12V / EPS12V Power Supply 100 - 240 V UL, cUL, CE, TUV, RoHS - Retail - $250 http://www.newegg.com/product/product.aspx?item=N82E16817703013
I'd say go for door number 6. PP&C are awesome PSUs, and while this is a pretty extreme system, extreme PSUs (over 750-800W) are completely pointless. As an absolute maximum (loading every component of your PC with artificial stresstests) you'd be drawing around 600-650 W. Trough normal intensive use, it'll never go above 500, even with those dual 3870s. One concern is that you should make sure you have enough connectors for the videocards on that PSU though. Otherwise go with the 860W version if you wanna fork out the extra cash, or go for the Thermaltake 750.
Have you calculated out how much power you need yet? If not try this before making your mind up- http://extreme.outervision.com/psucalculatorlite.jsp
