{MOVED}Alienware M17x Newer Video Cards?

I am currently running:

BIOS A07        (3/10/2011)

Intel Core Quad CPU Q9000 @ 2.00GHz (6MB Cache)

8GB Memory

(2) 500GB (7200rpm) Seagate Hard Driver

(2) NVIDIA GeForce GTX 260M 1024MB Runing in SLI

                    Main Video Card: 96RJ4 

                    Second Video Card: 4WGVV 

These are the other Video Cards that are avaiable from Dell for this computer:

X648M Nvidia GTX280M
X203R Nvidia GTX280M SLI
G51FX AMD Mobility HD4870
NHCHW AMD Mobility HD4870 CFX

I would like to know if anyone has had any luck installing a new card from NVIDIA or ATI for the M17X?

Like the NVIDIA 400 / 500 / 600 Mobile series 

                ATI 7000 Mobile series