I've got a stash of very small diameter arrow shafts I bought years ago when an archery shop went out of business. I'll be using them until gone.

I've been looking at carbon fiber tubes for pushrods (to save that final quarter ounce for park flyers) but been told that CF rods might cause radio interference since CF conducts. Whatever the truth of that, I weighed a fiberglass arrow shaft versus a CF rod and decided that the CF wasn't worth the minute difference in weight versus the monumental difference in cost.

BTW, the fuselage exit holes for the elevator pushrod and rudder pushrod are located perfectly if you plan to run the rods to those two surfaces' control horn's innermost hole.... which is a really bad idea for this a/c if you want to come close to the suggested rudder and elevator throws. I wound up with the rods connected to the servos' inner hole and both surfaces' horns' outer hole and still have more than suggested throws.