Alienware x51 R1 to R2 motherboard

Jun 30, 2018

I have an R1 with a R2 powerboard and I was thinking of just getting an R2 motherboard so I can use a 4790 as an upgrade to my 3770. I am in Canada and its rather hard to find a lot of good used stuff. Could anyone give me point in the right direction in obtaining an R2 motherboard for my x51 R1?