How much power should I used for the new intel and AMD CPU's
What watt's should I used
That depends on what else is going to be in the system. If you are putting in a mid range graphic card then you will want a 400 watt psu. If not, then 350 would be fine. Also, its not only the watts that are important, but the amps on the 12 volt line that are important too.
350 watt HERE
400 watt HERE
FSP is a good brand and fairly inexpensive.
I think I need one with SLI Support for my video Card
would a 450 watt power supply with SLI support work?
or how does the new SLI Video card work with the power supply
Here is a good one that is SLI ready and is a good brand. http://www.newegg.com/Product/Product.asp?Item=N82E16817194011