I can't really speak to the BCM barrel qualities, but here's my 2 cents about the upper:

I don't install anything but match grade barrels on my own AR's any more. Even for action shooting weapons, the difference is worth the price. Besides the accuracy, clean up is one of my favorite things about match grade barrels...

I'm NOT a fan of quad rails. I'm not a fan of the look, and they aren't as comfortable in my hand. Spend a few min holding on a target and you WILL notice that you have a rail in your palm, instead of a smoother forend. A new forend can be added later if you ever want to add other accessories, quad rail forends usually run in the $75-125 range. But that's just my preference, your mileage may vary...

I DO like the MOE stock, as far as telescopers go.

I'm not familiar with the XTR tacticals, do they have the same insert system as the Signature Zee rings? I'm quickly becoming a big fan of the Zee rings for optically centering scopes over the bore.

All in all, sounds like a good set up. I'll be looking forward to seeing some results, on paper AND on fur!