Re: Ambi side-charging upper besides LAR
Have you looked at the Adcor BEAR elite?
The rifle is a piston system (AR-style), and has a forward charging handle under the top rail of the hand guard. It's switchable from side to side (making it ambidextrous).
I got a chance to shoot one. They seemed at least as accurate as a typical production AR (maybe a little better than average). Perhaps they were not quite the accuracy of a high end AR, however. They weren't the cost of a high end AR either.