I would run either a 11x5 APC or a 12 1/4 X 3 3/4 APC
Both props do well on the AX.
And as farr as I remember the Funstar should come in well under 5lbs and if it does the AX will do well.
If you want some extra kick get a Tower hobbies brand 46 sized muffler, Its abit long and dosnt have cooling fins.
I run one on my AX mounted on a Hanger9 twist and its nutz, i have unlimited vert at half throttle.