Any .46 will be excellent power for your 4*. The Saito .82 will over power it to a great extent. Since you are still learning to fly, I would stick to the .46.

I do recomment you shorten the wing by 1 rib on each side and add an inch to the rudder. Otherwise it will be pretty tame compared to your Super Sportster. Stock, the 4* is a low wing trainer.