The big Harvard you already have calls for a .90-1.20 engine, and the weight estimate of 4.5 to 6.0 kg makes me think it will really need a 1.20

There are no trainers, that I know of, that can handle a 1.20 engine.

The SIG LT-40 (kit or ARF) has around 70 inch wing span and only requires a .40 or .46 engine. Most other trainers this size require a .60 size engine.

Another popular trainer, that's available in the UK and the US, is the Hangar 9 Alpha:
http://www.sussex-model-centre.co.uk...xd.asp?id=4757
This one is the 40 size with 63 inch wing span. There is also a 60 size that's about 70 inches but I didn't see it on this web site. I'm not very familiar with UK vendors so this is the only one I found. Sussex has several pages of trainers.

I am not a very good pilot, yet, but I really enjoy flying. Once you go up for the first time, you'll either be hooked or totally not interested in continuing. There doesn't seem to be any middle ground. If you're hooked you'll really start collecting planes. I have 4 flyable, two under construction, and two stashed kits. I had to switch from ARF models to kits to slow down the growth of the collection.