This is a trick question...right?!
My Tribute's rudder starts to flutter when it gets going "fast"...

I'm using a 12 X 4 APC on an O.S. .46FX w/ Tower muffler...14,000+ on 15% (straight up like a rocket...but I don't use WOT in level flight for more than a couple of seconds )

To answer your question...I'd say the 9 X 6 (or maybe 9 X 7 ) would work, but don't expect much in the way of speed from that thick winged, draggy airplane...