For the Micro Skydiver a high lift, 1.2m wingspan airplane is plenty big enough. If it can carry 10 oz. you are good to go. For example you can use the 1.5m FMS Cessna, 1.3m Carbon Cub, 1.2m Timber X 1.2m, 1.4m Piper J3 Cub or Grasshopper, 1.2m Decathlon, 1.4m Freewing Pandora, 1.5m DHC-2 Beaver, 1.5m Kavan Pilatus PC-6 Porter, 1.62m Nexa Piper PA-18 Super Cub Burda and many more. Of course, the bigger and more power the faster you get to jump altitude.