I acutally have not flown that many different trainers myself (that I can idenfity and remember), so I'm going to have to avoid getting too specific.

The LT-40 is a great plane, but I don't think it's a good choice here, too limiting too quickly. I haven't flown it with the "sport wing" though.

I did fly a PT-40 years ago that was a lot of fun. I think it had been modified with less dihedral than stock though. based on personal experience, this would be my choice. Or an ARF that was as close to it as possible. (ok, I went and checked out the current PT-40 ARF, and I'm not sure it's the same wing as the one I flew years ago, so I'm uncertain here).

I personally have a Hobico Airvista ARF, it's a good flyer, but really doesn't do the fun stuff very well. (and I have some gripes about it's construction, but that's another story). I use it to train other guys at times, so I have resisted the urge to shove the CG way back and crank up the rates though, so it might have more potential than I know.

I flew a guys Avistar, he had a .46 in it, and it zipped right along, I had to re-prop him and reduce his throws to slow it down enough for him to keep up with it. (I don't think it was set up as per instructions). It might be a good choice for you. It can fly well as a primary trainer (though not as slowly as the AirVista), but can be turned up as well.

In general, look for something with a semi- or fully symetrical airfoil. Or, with at least some curve on the underside of the wing from the spar forward to the LE. That will help a lot with inverted flight. Also, put it together with out too much dihedral, maybe 1" at the tips.

(I just poked over to tower's website, the Avistar does have a semi- symetrical airfoil like I thought. The AirVista is flat as a board from LE to TE, and the AirVista carries over 80 extra sqin of wing, making it more of a floater).

In another thread on here, someone was saying they used a stick as a primary trainer. You might look at some of the stick clones, many of them really do slow down nicely, but can be a blast to fly.

Another suggestion, you might think of going SPAD, or buying any random trainer and putting on a flat SPAD wing later to put life in to an overly stable design. With a little wing saddle modification, you can usually stick a smaller, symetrical wing on a trainer fuse and get a totally differnet flying plane. The spad website is www.spadtothebone.com SPAD wings are really fast and cheap to build once you get the hang of it, so it's no problem to whip up a new wing to adjust the performance of an existing plane.