Have you thought about a P*?
It's real close to a common V2 but I can't say for sure how the fit is. When I started my Ares quest (SR25) the easiest fix wast to buy a spare gun, run it, and wait on the parts (tappet plate and hopup).
Then 2 years later sell the B rifle.
These are the guys that got the parts in stock eventually.
http://www.uncompany.com/
I also need an upper receiver that a couple years straight from Ares and when it arrived it was cracked; they don't QC check stuff till after the gun if fully assembled.
So that was my first and last go around with Ares. Even if they made something so amazing and desirable that was at the top of my wish list I can't see myself buying anything from them again.