how does your car run? If it stutters, then yes, move it further away (the turbo may be causing turbulence in the intake and the MAF has a hard time reading correct amounts of air), if not there is no reason to relocate it. Moving it to the throttle body side would make it a 'blow thru' setup, research it because Im not sure how much boost a plastic MAF can take before shit inside of it blows apart (this also depends on how much boost you want to make). Other than doing blow thru it is pretty hard as you know to get an 18" span between the MAF and turbo. Maybe switch to a smaller mushroom shaped filter and have your intake dip down toward the front left corner.

EDIT: BAH! just saw you had surging issues. I take that to mean your car falls flat on its face sometimes or stutters?