RE: Control line trainer
Most people suggest starting C/L by building a kit. Good advice, but if you're like all the RC guys, the Tower ARFs work for C/L as good as RC ARFs work for RC.
Their two stunter ARFs make good stable airplanes for learning to fly, but produce many, many pieces when you stick 'em, and you will. The reason most people started out with a Ringmaster years ago was they were so bloody simple and not so hard to part with when they were turned into parts.
If you do go with a kit, make patterns of all the parts. You can build a 2nd Ringmaster or such for about 1/4 the cost of a kit.