Keep in mind the pads EK uses on all their blocks are only ~3.6w/mk. You really dont need super high end pads. 

I think it all depends on what you are aiming for but any kind of thermal pads is better than a gap of hot air.
 
I'm hoping higher end thermal pads and paste can allow more applications to run without the fans kicking in. I like silence!

For my understanding " I called EVGA support and they  have no idea" the thermal conductivity of the pads are around 6 W/mk. 
I went to the Sin Etsu site and the pads that they have are 3.5 and 6 w/mk so is not as good as a Fujipoly or a Thermal Grizzly one.
 
For my understanding all the pads  should be fine with a  thickness of  1.5 mm  EXCEPT for the wide one " the one on the backplate " that is supposed to be at least 2mm thick.
 
My thermal grizzly thermal paste and Fujipolys should be arriving this weekend. I will post my results as soon as possible. Thank you everybody for the replies, as a side note I will keep buying EVGA because even when they made a mistake they are still really trying hard to make it right for us.
 
PS: I will ask girlfriend for a waterblock kit for my Christmas gift