Those are very awful alternatives to what he's making. You'll only get a small fraction of the performance you'd usually get from whatever card you're using due to the low bandwidth of mini-PCIe or M.2 or whatever you're using. An MXM to PCI-E 3.0 adapter would allow for full 16x bandwidth and deliver the utmost performance possible. I currently have a Thunderbolt 2 eGPU setup which has more bandwidth than both of those and it's still choking tremendously with my GTX 970, or any other card I try to throw at it. This adapter OP is making is a very worthwhile endeavor.