I did sorta a find a solution...and I guess the problem is as solved as it can be right now
Here is what I know and what I did to make things work for me...you folks decide if it worth the trouble
Ok so the heatsink is positioned baddly casue of it size so it blocks the placement of nice higher end card; and the second PCIx slot is only x4. Aso you can't use a double slot card as there is obviously no physical space becasue the USB port, NIC peripherals are right where a 2nd exansion slot would be to accomodate such a unit.
So your limitation for a PCIx graphics card for the x16 lane is about a 7 inch long single slot card.
And as far as I can tell (or atleast a month ago when I got mine) the best candiate for this is the PowerColor AX5770 1GBD5-H Radeon HD 5770 1GB 128-bit GDDR5 PCI Express 2.1 x16
http://www.newegg.com/Product/Product.aspx?Item=N82E16814131330 (Currenlty $20 cheaper than when I got it)
Now you run into the problem of your powersupply just not being enough....And ofcourse Dell's propriatary 24-Pin Micro-ATX motherbard connector....
My solution for that was to purchase the "KDM HP-24MINI ATX Power Supply Cable"
http://www.directron.com/hp24mini.html
Then I purchased a "24-Pin Female to 24-Pin Male ATX Power Supply Extension Cable "
http://www.microcenter.com/single_product_results.phtml?product_id=0319755
Some of you might have already guessed where I am going with this
Anyway, the KDM HP-24MINI will not work as Dell used a propietary pin-out on the 24 micro-atx power connector on the motherboard. They were atleast kind enough to stick with the standard cable color coding for the wires.
So essentially I cut of the 24Pin Male connector from the KDM HP-24MINI and cut the female end from the "24-Pin Female to 24-Pin Male ATX Power Supply Extension Cable " and used the Dell Power Supply Pin Out to create my own (soldered the wires per the pinout) "Dell 24 micro Male to Standard 24 Pin ATX Feamale" connector.
Doing it this way I didnot need to splice my OCZ-ModX 600W power supply cables.
The custom conenctor works great. If you have ever worked with wires doing the above shouldnot be a problem. Just makre sure to follow the pin out correctly for the DellMircoATX to StandardATX conversion. Have been playing Warcraft3, Prince of Persia: Forgotten Sands and now StarCraft-II all at maxed settings wihtout any problems (Win 7x64) and the card hits about 70'C at high loads.
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24 pin 1 2 3 4 5 6 7 8 9 10 11 12
Dell GRND GRND +3.3 VDC +3.3 VDC PWR_OK GRND +12 VDC -12 VDC GRND PS_ON +5 VDC +5 VDC
13 14 15 16 17 18 19 20 21 22 23 24
Dell GRND N/C +12 VDC +3.3 VDC GRND GRND +12 VDC `+5 VDC - Standby GRND +5 VDC +5 VDC +5 VDC
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Std24 pin 1 2 3 4 5 6 7 8 9 10 11 12
OCZ-ModX +3.3 VDC +3.3 VDC GRND +5 VDC GRND +5 VDC GRND PWR_OK `+5 VDC - Standby +12 VDC +12 VDC +3.3 VDC
13 14 15 16 17 18 19 20 21 22 23 24
OCZ-ModX +3.3 VDC -12 VDC GRND PS_ON GRND GRND GRND N/C or -5 VDC +5 VDC +5 VDC +5 VDC GRND
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PIN Assignments
Dell 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15/19 16 17 18 19/15 20 21 22 23 24
OCZ-ModX 3 5 1 2 8 7 10 14 15 16 4 6 17 20 11 13 18 19 11 9 24 21 22 23
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Sorry but I don't think I can upload an attachment here.
The "Pin assignments" are essentially those pins that I connected together in my custom adapter. For exmaple Pin 1 from the Dell needs to be connected to Pin 3 (+3.3V) for the standard Power Supply. Pin 15 & 19 from the Dell both get connected to Pin 11 (+12VDC). Send me a note and I can email you my color coded excel sheet.
Hope this information helps others out there.