Figured I'd throw my hat out there. I have a smaller RV-4 kit comming out mid-february. Not quite a parkflyer (thugh it's definetly a small field flyer)- gonna be a bit faster - but never-the-less -It's an RV-4. Should be a good match for a Mega 16/15/x or Hacker B20L. We are flying it on a GWS-EPS300C and it behaves well - but motor life tends to be an issue with the 300 size can.