Stay with OS, TT or the Irvine. The manufacturing standards of the other brands are not up to the quality of these 3 manufacturers.

The LA would fly your trainer fine, but if you want something higher performance in the future then you should consider a ball bearing .46. If you do go with a BB .46 on your trainer you will have MORE than enough power, so use the throttle control accordingly. When you are really comfortable flying your trainer, the BB .46 would be a perfect match on an Ultrastick or similar 2nd airplane.