I'd buy a trainer type (or Stik equivalent) just to have around. I've progress onto my 4th plane and every now and then it's nice to bring that trainer to the field just to putt around in the sky rather than burning holes through it or tumbing incontrollably... Also after you grow tired of it, it's a good start to do some kit bashing. A member in my club took his Avistar and put 4 servos in it's wing, and enlarged all the control surfaces. He's programmed the plane for crow and using a big 61FX up front, the thing is more aerobatic than an Ultra Stick! Another club member has a LT40 that has 3 servos in it's wing (flaps) and can literally stop in the air.

The best thing is that trainers become great beater planes. I've learned a great deal about plane construction and repair. And since they're a relatively cheap commodity, there isn't a huge emotional attachment, so I get to "play" around quite a bit with it. My Avistar currently has high rates set to over 150% recommended deflection and is almost as spritey as my low wing aerobatic model. I try new manuveurs on the Avistar before any other planes.

Since you're already somewhat familiar with flying, I'd recommend a trainer with a semi-symmetrical wing (Hobbico Avistar or World Models Worldstar), or maybe even a Stick Plane (such as GP's Big Stik, Hanger 9 Super or Ultra Sticks, or World Models Super Stunts) which would be an aerobatic step up from a high wing trainer type. While the LT40 is a great flying plane, it won't be as aerobatic as the ones I listed above due to it's flat bottom winged.

Enjoy!