Lots of options here. I don't know that I'd put a Saito FA62 in a trainer, but it is a possibility and would be a sweet choice. Might be an expensive "ouch" in the event of a dirt-knap. If you can get the K&B .40 churning (I'd try it on a test stand first) you could put that in a trainer. I like the Global RCM 40 (which has wing bolts and a two-piece wing if you so choose).

The advantage to a .60 size trainer is that ther are easier to see amd less wind sensitive