I was under the impression the Tiger Bipe was no longer available, but if you can get one I would think you would like it for 'sport flying.' The .54 4-C should be plenty of power, but might require some weight added near the tail to balance at CG. Prop clearance may be an issue, but repalcing the stock main wheels with large diameter would solve that. I have no experience with th Ultimate .40, yet.
Last year I bought and flew a Tiger Bipe ARF, with a Magnum .40 2-C. I left the wheel pants off (always do) and changed to 2 3/4 inch mains for better handling on our grass field. I had plenty of power at our altitude (100'), not unlimited vertical, but scale-like takeoffs from our grass field at about 3/4 throttle. The four-stroke's torque should offset for Omaha's slightly higher altitude (I grew up in the corn country 150 miles to the west). From my point of view Tiger Bipe flew nicely at half throttle in level flight, so only used more than that for up lines, loops, etc. Slow flight controlability was good, with landing speed barely faster than an 'Alpha' trainer. Loops of 40-50 feet diameter were easy, with full throttle until 'over the top.' Altitude gains of 50 -70 during Stall Turn, and until 'fall off' during vertical rolls. Reasonable response from the ailerons (bottom wing only) using the suggested settings. Like most bipes it does not do axial rolls, but has slight variation in altitude as Elevator is definitely required (with suggested CG) during rolls, as well when inverted. Also like most bipes, it loses speed quickly when trottle is reduced. For landings I could take my pick of 'wheel landing' or 'three-point.' However, had to make "very" smooth transition to 'nose up' for a 3-pt, or it wanted to balloon slightly. I had a lot of fun with the Tiger Bipe.
After about 30 flights I sold it to an acquaintance who 'needed a training biplane', and went back to flying my Saito 150 powered, Super Stearman. [8D]