Get the Venus II (.90 size) - I promise you won't regret it. It is an absolute joy to fly Big difference between 40 size and 90 size in flight characteristics.

If you absolutely want a .40 size, get the Venus 40. It's a pound and a half lighter in weight than the other two. I've had a couple of Phoenix planes and they are built strong but heavy. All are very good quality.

OS 55AX is a great engine for the Venus 40.