I did manage to get it working!
With the DSDT override in place and with the help of setup 1.3 I managed to assign my eGPU to a 36 bit memory and now it is running smoothly.
My setup is as followed: HP elitebook 8560w, with an intel core i7-2630QM @2.0GHz and 8 GB of RAM. Internal GPU is quadro 1000M.
GTX 750Ti + PE4C V3.0 adapter from Bplus.
Corsair CX 430 PSU
And an external Samsung tv screen
As i said before most important is the DSDT override and setup 1.3. Other then that i had some trouble with the GPU drivers, but reinstalling them and not doing automatic updates works for me.
The one doneside is that i cannot restart my computer with the eGPU attached, i have to shut my laptop down completely.
Did not have the chance to get benchmarks and such yet, but might do that in the near future.
Hopefully it helps!