AK105 build questions: 1.6mm Receiver and Barrel/Trunion fit

I'm starting on an AK105 build (5.45), and was going to use a bulgarian AKS74 kit from Ohio Rapid Fire as the base. The barrel assembly would be replaced with a AK105 setup from k-var such as this:

http://www.k-var.com/shop/product.php?p ... 274&page=1

1) I assume that since these are both Bulgarian in origin and both 5.45, the interface of the barrel to trunion should be fine and there should be no major fitting issue even tho the dates of production differ by 10+ years probably. So some light sanding, pressing the barrel in, headspacing and drilling the barrel pin hole in the barrel would be about it. I have done this before with romainian ktis with no problems but figured its always good to ask first. Of course, this is all after the NFA tax stamp approval.

2) I am considering building it on a 1.6mm Elk River receiver. I know there would be some milling/grinding required on the trunions and bolt carrier but was curious if anyone has done a 105 build on a 1.6mm receiver? Is it even worth the trouble? I like the heavier receivers; should I just consider building it on a Firing Line milled receiver? If I went the 1.6mm route I assume some longer rivets may be needed. Any info? Thanks