I know you don't like the M16s, and mine is, but to chime in, I use both a 4x32 scope and an aimpoint M2 with a FTS 3x magnifier, depending on the game. The scope is good for range (keeping in mind that it IS airsoft, so you've got a realistic range limit) and the M2 is good for distance with the magnifier, and flipped to side, good for closer ranges.
It's all in your play style, best is to hang out with guys who have the stuff you're looking for, ask if they'll let you fondle a bit, and see how it suits you. Sometimes its just trial and error.
KJW SIG P226R -- WE 1911 Punisher -- KSC USP Tactical -- KWA USP Compact
KWA MP7A1 -- WE M4A1 -- WE KAC PDW -- WE G39K