Cheap PSU's keep packing in!! What devices use what watts?

[originalblend]

I have recently bought what I think is the best power supply for the money £100ish. I hope it provides enough wattage for my system (should I get another graphics card for SLI) I have a lot of HDD's and am unsure what wattage they use and have had a lot of problems with psu's and UPS overloads in the past as my system is rarely switched off.
Any advice from fellow riggers would be most appreciated!

Thanks for any help

OBlend..

 

[muffins]

http://www.extreme.outervision.com/psucalculator.jsp