Brison 2.4 will give you plenty of power, even on a pitts muffler. Keep the weight at 14-15lbs and you will be fine. I have one in a 14lbs Extra, will pull out of a hover well. However we are at sea level, what altitude you at ?
I have lots of experience with Bipes, Had the Lanier Pitts, a little smaller with a Fuji BT 32, OK sport plane, not to heavy at 14lbs. Flew fine! Fuji was not strong enough!
Also had a Weeks Solution, Weeks Special, Bucker Jungmann, and now a Ultimate. All flew well, however bipes have a little more pitch roll coupling. But can they ever tumble nice, and they look cool too. Just my opinion.
Many motors would work fine, Brison 2.4,ZDZ40, Evolution/MVVS 45, Taurus, BME, and the list goes on. If I was doing it I would try the MVVS/Evolution 45. Light, strong, good design, and people seem happy
The Bisson pitts for the ZDZ 60 will bolt right on from what I have seen, have fun.