Nitrovein, welcome to RCU!

The proper name for what you are describing is a "stabiliator" which is the combined names of stabilizer and elevator.  Or some just call them "all flying tails" to indicate that the whole surface moves.  It's not really right to call it a "canard" if it's on the rear.  The term "canard" refers to the forward control surface on a canard style of airplane.

Really other than on a sailplane where it has some slight drag advantages due to not having a hinge line and also because the airfoil is always oriented directly into the flight path other than the slight angle needed to lift up or down there's really no big advantage.  And on many models it makes building them more difficult to engineer and construct a truly slop free hinge so that the tail doesn't wobble.

On some models there's good reasons to make the tail with a proper airfoil shape.  But on simple sport models a flat plate actually works just fine.  Flat plates show up on many models and full size aircraft throughout the history of aviation.  The venerable J3 Cub uses a flat plate made from fabric covering a simple flat pattern of tubing bent and welded together.  And many, many other full size planes use this same easy to use method that produces a flat plate for the tail sections.  Unless your model will be used in some competition where the last bit of drag matters there is not that much to suggest that a flat plate is all that harmful to the flight of most models.