Having built, flown, and trained students on the LT40, I can personally attest it is perhaps the best out there. Best of all, it's virtually complete with just about everything (minus covering and the usual building supplies). And it ranks right up there with the 60's as far as size, but in a 40 size package. I did have a student one time, however, put in a little wore out runt 35 in his and it DID NOT like it. As previously stated, go with the higher side of the recommended range around 40-46. With the Senior, there's a lot of stick balsa and requires exact angular cuts with more time involved (and requires mods for ailerons) but looks absolutely beautiful with transparent covering, although crashes tend to get very, very interesting with them. The LT 40, on the other hand, has lots of ply reinforcement and can take a lot more abuse. You won't be disappointed with the LT 40 and the OS 46, but I'm afraid you'd be a little unhappy with the trainer 60/OS46 set up you're originally contemplating.....