I need some help in deciding which mobo/cpu to choose.

My requirements are:

1) Preferable Intel CPU (4 cores) which should be able to address 64GB RAM.
2) 64 GB RAM onboard (4 slots -> 16 GB DIMM ?)
3) Support for USB 2.0 and USB 3.0 (and maybe 3.1 as well)
4) HDMI/DVI onboard
5) 6 or more SATA3 or better connections
6) ATX form factor

And of course at an affordable price... (I live in Norway)..
I'm not into gaming or video editing, but I want to be able to run some virtual machines along with my host system (which will be Linux : either Linux Mint or Ubuntu).

Intel makes very solid mobos that will probably meet your requirements. Go to their web site and check out their system boards. I've been running a dual processor server/workstation mobo for almost 8 years without any problems.