A good pattern plane is typically a mid wing, no dihedral, streamlined plane that will perform precision aerobatics without changing attitude throughout the maneuver. However, they can also be low wing, with very slight dihedral, but the best are not. A 3d ship will be much the same (mid or low wing), but mostly low wing with huge over-sized control surfaces. It will be constructed lighter, and will require an oversized engine (for hovering) and strong servos to move those controls surfaces.
I would not really suggest either one of those two as a third plane, especially since (by your own statement) you have not even built your second plane, let alone flown it.
However, if you insist, then you might look at the hanger nine pulse series. They are very nice flying airplanes, with good tendencies taht would make for nice second airplanes, yet they are still fairly capable aerobats. Probably not a true pattern ship by the strict definition, but definitely a point and fly machine...