i've also used sullivan golden rods sucessfully. i think it's a little easier to work with than the braided cables.

there are also people that mount a bell crank on the motor mount and lead a rod back to the throttle horn but i think that's a little much. the bend, the braided cable or the golden rod would be fine.

the other option is to mount the servo in front of the firewall. i often do this on planes i know will be tail heavy (most bipes and warplanes). the HS-81 is my favorite servo for this application as it's small enough yet has a good amount of torque. i cut out a ply servo tray, brush it with thinned epoxy and mount it screwing it into the side of the engine mount and add epoxy as necessary. the tray would be mounted so that the servo sits "below" (relative to engine) the engine. then a run a short rod to the engine. voila! easy. i'm sure the zero would need more than a 52 to balance so having a small servo up front would help you get the optimal CG without additional lead.