From what I've seen so far the G&Gs have both excellent internal and external quality. Even though you're limited to plastic recievers I have to admit they're really good. I've been using 2 G&G M4s as rentals for 4 months now and neither of them have had any issues. If you're hell bent on getting a full metal you can always buy a good aftermarkt metal body for $100 - $200.
Just playing devils advocate. I still hope you can get AV'd soon and find what you're looking for on the boards.
Thanks for the info, Harbinger; I've been wanting a monitor lizard for my M4, but I was afraid I'd have to settle for an iguana.
No problem Tex. I've been attaching monitor lizards to guns since '95.