I would recommend the Sig 4* series. Actually a 4*60 would be ideal as you'll get into a larger plane and engine. It is very stable, glides vey well, and can do some good
aerobatics. AND once your ready for a little more action, cut the wings down be trimming to the first set of ribs, from 71" to ~64" and it will be much snappier. Actually, if you dont want to invest in another engine, get the 4*40 (if still available?) and trim after a season or two (depending on how much you fly and your comfort level).
I started with a trainer, then got the 4*60, and after two seasons trimmed the wings....