RE: 4stroke vs 2 stroke
For getting back into flying, choose an engine with the adjustment needle behind the engine. That's pretty much every fourstroke, and some of the twostrokes. Keeps your fingers away from that knuckle-eating prop.
Both are quite suitable, but there is a difference in price. I think you might want to choose one of the less expensive engines, for now.
Good luck,
Dave Olson