This an adapter which you plug into your rx and you plug 2 servos into it. Both servos should perform in an identical manner. From what I saw in MinnFlyer's review of your plane it already has 2 pushrods installed (one to each elevator half). You would connect one pushrod to each servo and both servos to this adapter harness and the adapter harness to your rx. There will be a very slight weight penalty but this is what the plane is designed for.
Adapter:
http://www2.towerhobbies.com/cgi-bin...?&I=LXH451&P=0
While this particular adapter does not physically "Y", it can be referred to as a "Y". There are others on the market that do physically split if your servos are further apart (like in the wings).
A Y-pushrod is a mechanical thing. It is done in several ways. I'm having difficulty figuring out how to describe it to you so you will understand. Is there anyone local that can help with this?
Here is another Y-harness, although it is too long for you it will help you get an idea: http://www2.towerhobbies.com/cgi-bin...&I=LXL307&P=ML

MinnFlyer- Got ang drawings?