Control rods
You don't have to spend that much money.
My local hobby shop had some carbon fiber rods for around two bucks. Dubro 4-40 threaded couplers JB welded into the ends work perfectly.
I used Air Wild 1" servo arms with Dubro ball links. This drops the control rods low enough so they clear the fins easily. Just to make sure I moved the servos out about 1/8".