I have found you can do just about anything with these planes but putting a 60 on a Nexstar would require cutting the side, foux cowels off and re-drilling the firewall for a larger motor mount. I would not even concider it unless you planned to put the plane on floats but even then it would be easier to put a 50 or 55 on it. You do not need all the extra "Bling" that comes with the Nexstar... and this is comming from a pilot that learned to fly on a Nexstar. Spend about $100 on a used simulator and get one of the two 60 sized trainers you mentioned... Locate a reliable club/instructor and get busy flying.