CPU discussion:

https://www.dell.com/community/Alienware-General-Read-Only/Recommended-CPU-upgrade-for-M17x-R1/td-p/5587047

and some GPU discussion here

https://www.dell.com/community/Alienware-General-Read-Only/M17x-r1-upgrade-components/td-p/5608673

I'm not sure that those GPU's will work in the M17x R1. I've never heard anyone getting those cards to work. I believe the 580M should be possible but people usually go for AMD cards (like the 5870) in these older models. 

Alienware Elimy said:

Intel® Core™ 2 Duo Processor P8600

Intel® Core™ 2 Duo Processor P8700

Intel® Core™ 2 Duo Processor T9600

Intel® Core™ 2 Duo Processor T9800

Core 2 Quad

Intel® Core™ 2 Quad Processor Q9000

Intel® Core™ 2 Quad Processor Q9100

Core 2 Extreme

Intel® Core™ 2 Extreme Processor QX9300

and the gpus are either:

GTX 780M or 880M with 980M if you want.

just update the bios to its latest version and thats it unless you have the 120hz screen option.

Oh, i was reading on the notebook review site that a guy did that.

but then someone else suggested the 5870 or something like that.