I would go with the ZDZ80 single. I currently have the twin in my second one as well as I did in my first model as well. I moved my rudder servos to mid ship and I am about 2" behind the tube. This is where the planes seemed to really want to be for my flying. Great IMAC flying and awsome 3D with out changing the CG one bit.

Here is a pic of SUK #1 (R.I.P.)

Chris Puckett