The bigger, the better!!
I used to tow using a 235hp Pawnee at Lleweni Parc (North Wales) in the early 90's in some very Interesting (Turbulent!) conditions and can honestly say that although the Pawnee is not the most comfortable aircraft to fly (being male and this is assumption only - like sitting in a birthing chair?!?) on more than one occasion the brute power and controllability ensured that I remained a member of the human race!! Give me a big throbbing powerplant and a short field take off ability anyday!! - a chippy with 235hp Mmmmmmmmmmm!!!
Expat Dave, Perth WA