Dell Inspiron e1705/9400 GPU

I think it's safe to say, that Dell laptops seem to be the most upgradable - at least that's the impression I have gotten reading up on them. You can change the processor, RAM, hard-drive and of course the GPU - the GPUs ability to be upgraded alone I think is almost unheard of in other laptops.
But is there any complete list of compatible GPUs (and dother parts) for the Dell Inspiron e1705/9400? Or indeed, are there any lists of compatible parts listed by Dell model so that others may benefit?
Some would say that whatever Dell offer on their website as options when customising your laptop are all the compatible parts. But I find it hard to believe that only two cards are compatible - the crappy X1400 and the excellent but very expensive Go 7900, two extremes, with no middling card whatsoever.
I have seen people referring to their 9400/e1705s with different cards such as the 7800 (I suspect this is what they used to be shipped with before the 7900 was introduced) and I have also heard of people putting in the even more expensive 7950 512MB (with modification?).
So does this mean that the older (and cheaper) GPUs they used to come with are also an option when upgrading one's GPU? As anything must be a step up from the Radeon X1400...

I guess in my long and rambling style I am implying that, wouldn't it be a good idea if a list were to be created that informed one of all compatible CPUs and GPUs (and perhaps RAM, ExpressCards and drives or whatever) with several different models of Dell laptops, any instructions for modifying that must be carried out with links to information regarding parts and perhaps even estimated costs of components etc. - which may save people from asking potentially annoying questions such as inquiring about compatible GPUs


EDIT: The list I am proposing could be formatted something like this:

 

Yes, I like your idea. But I’m afraid I don’t have any valuable information to add. However DELL is not the only manufacturer with upgradeable graphic cards. There is a technology called MXM (Mobile PCI Express Module) which was created by nVidia to make a standard socket for notebook graphics adaptors, but didn’t work out as expected. But there are few notebook models with MXM cards, you can learn more about the compatible models at mxm-upgrade.com. I'm not sure where, but I remember reading somewhere that DELL also uses some variation of MXM.

More reading material : nVidia MXM

 

Well, if you're adventurous, I guess you could throw in the screen type (Matte vs. Glare) as well as the Hard drive.