Alienware Area51 R2 Japanese model

Hi,

I recently started upgrading my Alienware Area51 R2 desktop PC bought late 2014 and successfully upgraded my video card from GTX960 4GB to GTX1080 8GB Gigabyte Xtreme gaming :D

Then unfortunately got stuck at memory RAM, I tried more then 5 different companies RAM but I failed every time. I realized that Dell Motherboard does not support other maker memory RAM so I then decided to change my Motherboard. But since Dell Japan does not support change of Motherboard now I'm stuck at what to change and how to change it.

I started searching for Motherboard information and here is the information I got from many different sites and also contact dell.

Motherboard: ATX

Maker: Microstar international

Product ID: 911-7862D2-12S

RAM: 16 GB DDR4 2133 MHz

Now I'm not sure which Motherboard can be replaced successfully, I wanted to replace it with MSI Z270 Gaming M7 Motherboard, please advise me if I can change it or no?

Also why does it not support any other company RAM?

HELP!!!