Trade: Sig 516 Gen 2 gas piston upper. 16'', 1/7 twist, 5.56

[luckyduck]

I got this in a package deal from a forum member and I'm looking to trade it. I'm new to ARs and I'm realizing that I'd rather go with the lightweight nature of DI over piston (not that this Sig upper is that heavy, but I want to go reallly light).

Looking to trade this upper for any of the following:

-a lightweight, pencil barrel upper (direct impingement)
-towards a 5.45 AK
-CZ 527
-9mm handgun
-Norinco or Colt 1911

Obviously I'd add cash from my end depending on the trade.

Low round count. Great condition.

Thanks!