Power Supply Calculation help please

Hi... Welcome to the forums...
Before we could go ahead and suggest things, it would be easier for us to help you better if you could read the sticky and copy paste it here...

*How To Ask For New Build Advice*
http://www.tomshardware.com/forum/261222-31-build-advic...

Your AMD940 will fit in Asus p5q with the hammer only. P5Q is a motherboard for Intel procesors, not for AMD. The power suply is more than sufficient.
For your AMD processor look for an AM2+ motherboard.

I do hope my update, with accordance to the thread guideline (my bad for not following), will be sufficient.

My Purchase date is within this week or two weeks from now. I will be using it for playing the latest games at the DX 10 level but without the eye candy (AA etc.). But the main function of this computer is to edit 1080i movies with the recent purchase of a Sony HD camcorder.

I will not be overclocking for the sake of keeping warranties, I will be buying mostly from Canada Computers or Tiger Direct. The monitor i am using is a 19' Viewsonic (non-widescreen and unknown if it can handle higher resolutions). Will be running all applications at 1280-1024. I may make use of the dual dvi and link two 17' non-widescreen monitors for editing purposes. My budget is around $1000-1100 before tax. Rebates are loved.

Processor:

AMD Phenom II X4 940 BE 3.0 Ghz
-retail

Ram: *updated because i found a better deal for my OZ ram

OCZ (OCZ2P10664GK) DDR2 PC2-8500 1066 MHz Platinum Series 4GB(2x2048) Dual Channel Kit
-retail

Graphics Card: *Can choose between the two (still deciding with respect to price)

Sapphire ATI 4850 512mb DDR3 ram
-retail
(is there a difference in the Sapphire toxic version? -retail

Sapphire ATI 4870 512mb DDR5 ram
-retail

Hard Drive:

-retail

With respect to my power supply, what will be the best wattage for my current build (i know i did quotes two video cards, but they have similar wattage)

Can i somehow cut costs without spending too much money on a Cosair TX series SMPSU-650TX 650W powersupply -link ? Also if possible, what is the lowest wattage i can go before my system is at risk?

As for the motherboard i am currently searching for one. Are there any which are around the same quality, price, and functionality of the Asus P5Q 775 Intel P45?

As for other questions, i have read upon how the new AMD Phenom II X4 940 BE cannot manage DDR3 ram well. So should i get a higher end mother board that does support DDR3 for upgradability purposes, or should i settle for less due to the fact that when upgrading the PC i would have to change a vast amount of it?

Thanks for reading and i do hope that my update has followed all guidelines.

Don't know squat about your intel mobo but,for your cpu you might consider the Gigabyte GA-MA790FX-UD5P mobo will take all amd cpu's and works fine with ddr2... 

Well how about www.ncix.com...
They have a price matching feature and have pretty low prices as compared to many...So search here also for good deals...
They have combo deals which would save some cash...

And for you mobo, the 790 chipset is like the P45 chipset for AMD CPUs...So go ahead and get this mobo...
http://www.ncix.com/products/index.php?sku=36414&vpn=GA...

or the one without onboard graphics...
http://www.ncix.com/products/index.php?sku=36856&vpn=GA...

Well if you want to go with DDR3, then yo would have to change your CPU as well as the X4 940 wont support DDR3...
Only X3 720, X4 810, X4 945, X955 support DDR3...

So if you want DDR3, then here is a setup that you can take a look at...

CPU
http://www.ncix.com/products/index.php?sku=38048&vpn=HD...

Mobo...
http://www.canadacomputers.com/index.php?do=ShowProduct...

RAM
http://www.canadacomputers.com/index.php?do=ShowProduct...

So if the budget allows you this, then get this setup...

I'd recommend this PSU.
http://www.ncix.com/products/index.php?sku=29896&vpn=SS...

And this GPU.
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

Buy from ncix and price match, and pay no PST outside BC.