The O.S. Max .40 LA would be a good fit for planes in a number of categories:

Trainers: Tower Hobbies Tower Trainer 40 MkII ($79.99), World Models Sky Raider Mach I ($99.99), World Models Sky LA Flyer 40 ($109.99), Wings Maker Wingman I ($79.99), Sig Kadet Mark II kit ($69.99)

Sport Planes: World Models LA Racer 40 ($109.99), Phoenix Models Dolphin 40 ($99.99), Wings Maker Wingman II ($79.99), World Models Sky Raider Mach II ($99.99), Sig MidStar kit ($89.99), Sig Kavalier kit ($72.99), Great Planes Escapade ($99.99)

3D & Fun Fly: Tower Hobbies Uproar 40 ($89.99), Hangar 9 Tribute 36 ($94.99), Tower Hobbies Fun 51 kit ($49.99), Great Planes Dazzler ($119.99), Phoenix Models Funstar 3D ($109.99)

The .40 LA, while not the most powerful .40-size 2-stroke on the market, is a good reliable engine that provides plenty of power for a number of high quality .40-size airframes.

Good luck and good shopping!