I had one when then first came out with a ST.90. Verticle was just OK. If your stuck on a two stroke go OS 1.08 or Webra 1.20. or maybe the new ST2300. I'm sure you will get some go four stroke replys. I would also push you that way if you had not mentioned your leaning to a 2-C.
Think about it though. A Saito 1.80 would be sweet on that bird.

David