Txaggie,
The TS70 should be fine on the rudder. I run a DS821 at 70oz on the rudder of my 2 meter pattern
plane and will pull a knife edge loop. I also use the same DS 821 servo on all my control surfaces
and it works very well. Only lacking in the snap roll where it winds up a bit before the snap. I run
them at 4.8 volts and the plane flies very well. If you are going to fly with 3d throws you might
want to think about something like the TS 70 all around.

With the 7Lb weight of the U-can it most likely won't see unlimited vertical with less than a .91
and hovering may even require a little more engine. Also as this plane is a 3d plane it has very
large control surfaces and for the basic aerobatics you will want to tone the throws down
to 12 degrees of throw or less on the elevator and aileron, Rudder you can use as much as you
can get. This will make the plane a little more forgiving as you are learning these maneuvers.