Is it [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXTDF5&P=0]this one?[/link]

Again this is my personal opinion, but I would not put a .91 four stroke in a 8.75-10lb airplane. I would go with the max recommended size of 1.20. These planes need speed.
Congratulations on your engine purchase by the way.