First ask yourself whats more important to you speed and aerobatics or looks and sound. If i had a choice for the same cost a four stroke and 2 stroke i would go for the 4 only because i prefer scale planes over sport planes. But the cost is a big part of my decision so im going to stay with the 2 stroke. Im not exactly sure but is .91 engine suitable for a 60 trainer seems a little big but i might be underestimating the impact sea level has on the plane.
Anyways youve found some people that can help you which is great, get your plane start it up and have fun.

Papa