Actro 60-175 would be a very good choice, I flew my smaller 1/4 Cub in around 15 scale contests and also used as a tug
for 4meter scale gliders perfectly with smaller 40-6 Actro, more than 40 flight hours, and never had any complaints about it.
If going a bit further on in size, below link a bit bigger one, 14 ft Super Cub, also outrunner powered.
http://www.rcuniverse.com/forum/m_15...tm.htm#1520815