Kelly,

If you go with the ZDZ or any of the glow motors then you'll certainly have no issues with the plane being tail heavy even with servos in the rear. In fact, you might be a bit nose heavy w/o the servos in the rear. But I'm sure you could be creative and move some weight back if that happens. The "true" elevator matching that you speak of is probably the best (and maybe only) reason to go with the DEPS.

I've put dual elevator servos on two pattern planes and had absolutely no problem getting them to track the same. I have a trick that I use in measuring the elevator throw. First turn the radio on and get the two halves so that they are perfectly level with each other. This is easy to do by using the tips of the stab as a guide. I then tape two laser pointers (the lightest you can find) to the elevator, one on each half, and aim them at my white refrigerator about 6 feet away. Shim the laser pointers until the dots are exactly next to each other horizontally. Now using the radio move the elevator up and down. Any difference in throw will be EASILY spotted when projected six or more feet away. I personally have never had much trouble getting the halves to track right with each other after I set the end points of each elevator half the same (JR 10X). NOTE: Your control horn lengths, angles, etc. need to be the same, but this is fairly easy.

Using the JR DS3421sa mini digitals I get many fights out of the plane before having to worry about it. My experience is that this approach is rock solid.

FWIW, I know numerous NATS FAI finalists (Quique, Andrew Jesky, Don Szczur all flying the Brio) that have the servos in the stab. I know in theory it can't be as exact as the DEPS system, but many people use the stab servos with great success.

I say this only because the DEPS system is more trouble than stab servos and I'd hate for you to think that it's a requirement to have an acceptable flying plane.

Best of luck,
Keith B