RE: Seagull Ultimate biplane 90 size
I had a Saito 1.25 in one. For me it was underpowered. It would sport fly it fine. Most of my planes are 3D type and it just felt down on power. Hover for example would be 90% throttle. WIth a 1.00 I don't know if it would hover at all. Maybe mine was a heavy example but it was close to 13lbs. Way to much for a Saito 1.25. Your gasser might be a better option. If you go that route plane on moving the elev servos to the tail. This should help with the CG.
David