GPU upgrade

I'm looking to upgrade my M15x's graphics card, and I wanted to make sure I get all the information & advice I need so I don't end up with a graphics card (or worse, a laptop) that doesn't work.
Current specs are: i7-720qm, 8gb ram, Samsung 840 250gb ssd, 1080p screen, gtx 260m
I've seen things about different power supplies, having to use cooling pads and grinding components, which are things I'd rather not have to do. Modifying drivers I can handle, but would rather not have to do too much of.

So far I've found a 560m, 670m, 675m and 6970m. These seem like decent cards that should work, at decent prices, but I can't be sure. Any of them actually compatible? Do I need a new bracket or heatsink or anything else? Any other cards recommended? While I'd love to go completely top of the range, I'm a cheap so-and-so, so bang for your buck is quite important.

Apologies, as I know I'm not the only one asking for help on this but, as I said, I really don't want to screw it up. Hopefully you guys can help

 

for ease of installation, and bang for buck, 660m is pretty good. with higher power draw cards like 675m you might have power issues. also stock 150w charger is enough to power anything that will run in m15x

 

I have a thread open above this one pretty much asking exactly what you are. I decided to go with the GTX 680m, and currently I cannot get it to work. Now this is probably due to my lack of experience, but right now I am stuck on the step after flashing the BIOS. If I get it figured out and the card up and running, I will let you know how it goes!

 

Ok I got it working, which once I knew what to do it was a very simple process. Going from the GTX 260m to the GTX 680m is night and day difference. I have turned Diablo 3 and Starcraft 2 settings on Ultra and done the most graphics intensive levels and the GPU handles them like it's nothing. I am extremely happy with my decision to upgrade, and I would highly recommend the GTX 680m as well.

 

I'm glad your upgrade went well

 

While I'd love to get a 680m, it's a bit out of my price range. I mean, it costs about twice as much as a 670m, but does it offer twice the performance?
Out of interest, did you have to use a different backplate or power supply for the 680m? Has it overheated, or even got worryingly warm? And I assume you had to mod some .inf for the drivers?

 

Actually, my computer is running cooler than ever. I have a cooling pad, new thermal paste, and cleaned out all of the dist from the vents. My temps stay like 65 degrees and below. I had to get the 240watt power supply. and yes I needed an inf mod for the driver.

 

680M isn:t actually that expensive anymore AND does perform 50% better easily. Especially if you OC the memory a little.