Photoshop/Rendering Workstation

Hello,
my first post here. I hope you people can help me out with the right choice. I'm a digital artist working with very high res files in photoshop. my files can be over 15000 px wide.
i actually worked with a dell precision 670 with scsi for several years. Since i also use rendering i'm also interested in cpu. so i'm not sure to go with a dual xeon or a core i7

Here are 2 systems i put together:

Workstation 1:
- Gigabyte GA-EX58-EXTREME
- Intel Core i7 950 BOX
- Mushkin XP3-12800 3x2GB Kit, DDR3-1600
- 2 x WD VelociRaptor WD3000HLFS, 10'000rpm (wanna do a raid for this. maybe i should take 2 more for a raid swap drive?)
- Cooler Master RC-840-SSN1-GP ATC 840
- Corsair CMPSU-TX750, 750W

Workstation 2:
- Supermicro X8DAH+, Intel 5520, LGA 1366
- 2 x Intel Xeon DP E5520, Quad Core
- 2x WD VelociRaptor WD3000HLFS, 10'000rpm
- Cooler Master RC-840-SSN1-GP ATC 840
- Be Quiet Dark Power BQT P7-PRO-850W (enough ?)
- Corsair TR3X6G1333C9, 3x2GB, DDR3-1333 (forced to use this 1.5v ram since the motherboard)

the graphic card i would take out from my old computer, its a quadro fx 570, i also have a quadro 540 .. can i use them both somehow maybe?

i also invest in some NAS backup solution so i can sleep well with the raid.

also do i need to take care of anything else with these systems? more power? more cooling maybe? hope you can help me out i'm not really up to date with hardware etc. any suggestions will be welcome..

thanks in advance and all the best from switzerland!
microbot

EDIT : ^ +1 I dint refresh the page before I posted my suggestions

Hi...
I certainly can say that the Workstation 2 would easily perform better than the Workstation 1 beacause of the dual quad-cores...
And dont waste money on the Velociraptors...
instead invest the money on SSDs...get 2x 60GB OCZ vertex in RAID 0 and have a 500GB/ 1TB for data...this setup would be far better than the Velociraptors...

And have about 12GB of RAM - 6GB for each CPUs...

You wont need that much power for both the setups...
A high quality 650W is more than suffice for that setup...

Hi, may I ask if Cooler Master RC-840-SSN1-GP ATC 840 is able to fit in supermicro X8DAH+ ? This is because I bought a icute Super A18 ( http://icute.com.tw/english/A18.html) and I can't fit it in because there is an extended part above the VGA/USB side.