NO TRAINER REQUIRED...THE TIGER MOTH IS A TRAINER
Don't buy an ARF trainer because you think it will be easier to fly than the Tiger Moth. That's simply not true. The Tiger Moth will be easier to fly than any ARF trainer you can buy.

IF YOU STILL WANT AN ARF BUY A TAIL DRAGGER
A BIG downside of most if not all of the ARF trainers out there is that they have tricycle landing gear. That won't prepare you at all for a tail dragger. If you really want to do the ARF thing my suggestion would be to buy a Piper Cub or some similar docile tail dragger. That at least would have value when migrating to the Tiger Moth.

HIGH WING...LOW WING?
I don't understand the high wing low wing concern. It sounds more like you’re preparing yourself for a P-51 Mustang than a Tiger Moth. I think it's over kill. My first RC airplane was the Great Planes Tiger Moth. I learned to fly on her and I still have it 9-years later with hundreds of flights on the log book. Model Airplane News rated it as one of the Top-10 ARFs of all time and the easiest they have ever flown.

BUILD A COOL TIGER MOTH
Don't waste you money on all those other aircraft. Build the Tiger Moth and slap in one of these cool O.S. IL-300 engines. I am attaching a link to a YouTube video of a Flair 1/4th scale Tiger Moth with the IL-300 attached. As soon as you hear the sound of that 4-cylinder you will forget about all of those ARF trainers. The second link is of a Flair Tiger Moth landing. She just floats down so easily. You won't find an ARF that lands like that.

[link=http://www.youtube.com/watch?v=0BcUvz_x8rw]Fliar Tiger Moth & IL-300 4-cylinder engine[/link]
[link=http://www.youtube.com/watch?v=sPGiotGanns]Flair Tiger Moth Landing[/link]