External GPU VooDoo magic?

Hey guys. I have recently been "inspired" by alienware with their external gpu dock thingy to make my own portable workstation. Right now I have a Lenovo T430 with the stock i5 (dual core ht) but I can buy a i7-3610QM (quad core) for a decent price. So I have the cpu bottleneck down. Now I need to figure out how to rig a card to this thing. There is an expresscard on the side that is not being populated but I can't seem to find bandwidth specs for it. After all I am planning to use a gtx 960 or a r9 280x. If you could give some pointers that would be really cool.

edit: Here's a thing- http://www.ebay.com/itm/EXP-GDC-Beast-Laptop-External-Independent-Video-Card-Dock-Mini-PCI-E-Version-/111682179200?hash=item1a00c6d080

Here is a video of someone who installed and reviewed one. He raises a few points.

I am not sure how the Alienware one works but this one, the same as your link, will not use the laptops screen and you need an external screen for it. It is more some thing that will only be used at home and then unplugged for using the laptop as a laptop on the go.

He aslo does not really point out that usually mini PCI is only a slow speed and it full x16 speed. Though this matters in varying degrees.

But if I run a card like a 960 will a expresscard bottleneck it?

That is what I am not sure of. The answer is probably but will it matter enough?

Eddit: Okay express cards are PCIe 1x which is very slow and a definite bottleneck. So that answered that. Moving on though is that a problem?

Maybe? Maybe not? I am having a hard the find people who have tried it but I am on my phone so my Google Fu is limited.

Well, what about expresscard 2.0? Does the t430 have that?

It seems that this guy did the same thing that I am considering but with some lower end hardware.

http://liamfraser.co.uk/projects/egpu.html

That x1 lane is a pretty pointless for a gaming scenario - even a 750ti will be held back, but for something like a cheap quadro for design it may be worth it, still wont be great though but may suffice for a slightly better workstation use case.
Tis a shame there is no proper thunderbolt and associated eGPU support.

The question is HOW MUCH will it be held back?