Snootch,
Both will work. The larger ailerons on the Kabriolin would give better slow speed rolls. It depends on what mauvers you want to practice. For tork rolls pick the plane with a longer fuselage moment. If the planes are the same basic size compare the distance from the trailing edge of the ailerons to the leading edge of the stab. The lignter airframes will also be better. I fly a H-9 Pizazz and it is also a good choice for your engine. Many IMAC pilots use this plane for 3D practice. (Its like arguing Ford/Chevy/Dodge >> pick one!) Practice will have more to do with pilot skills over the minor difference of any of the above choices. Bill