Welcome to RCU , glad you made it back to the world of RC
I have this plane, and have had a ST.40 , Evo .46 and a Magnum 4 stroke .52 in it . The 4 stroke is what I`ve stuck with and my second choice would be the ST.40
The 2 strokes work fine ,but do not have the same pulling power as the 4 stroke. The plane just handles better . No need for speed , it`s a trainer.
For a 2 stroke , the O.S .46 is the easiest motor I`ve ever dealt with., but if you are confident with your tuning skills , don`t be afraid of the lower end engines . Once broke in and tuned they run just as will as an O.S and most have more power.
I make this recommendation based on fact , not personal preference . Let the beatings began.