If you are note averse to tail-draggers, converting the Duellist to a tail-dragging config will take care of the prop clearance problem, and also cut your weight down a little by eliminating the nose gear/wheel. This is what I did on mine.
Alternately, use 3 bladed props and you can go about an 1" smaller in diameter.
I also moved my mains out into the nacelles to provide a wider track.
My kit was the older die-cut kit. The wood for the ribs was extremely dense and heavy, I replaced it with medium density balsa and shaved 3 oz. in the ribs alone!!!
I thought the 7 degrees of downthrust on the engines looked excessive, but it's just right. Plane flies beautifully and tracks nicely in all phases of flight. Just build it as instructed.
A little more info on my duellist at this link:
http://www.elliotfan.com/temp/duelist.html
Hope this helps.
-E