Arbud, you might want to consider an Arms #36ex...that will give you the extra forward length you need to provide the proper eye relief with your face where you want it. Also, it raises the flat top up about 1/3 of an inch...you can still use a medium ring, and it'll make it much easier to charge the rifle without needind the tac handle.
Here's a pic of my 16" with the scope mounted on the #22 high rings, and on top of a #38.
I outsmarted myself...had I known I was gonna put these handguards on, I would have gotten the #38ex...for exactly the reason you're discussing here. As it sits now, this setup has the scope a little higher than it needs to be, but it still works.
[img]http://img.villagephotos.com/p/2003-7/188491/modular1.jpg[/img]
BTW, the Aetec scope needs a little more eye relief than some of my other scopes, but this setup seems to be perfect for it. Notice how everything is mounted as far forward as it will go...you can see why the #38ex would have worked better. Of course, I can't go too much further, 'cos then I got the front sight to worry about. BTW, the #36 does NOT have the rear sight built in...so it would not cause you any problems in that regard.