Pizman, I love the Saito 1.80 I have, and it is a great running engine. But the extreme thirst for high nitro fuel has seen me flying it less and less. I can fly my two gas planes all day long on much less than a gallon of gas/oil mix. The Saito can easily suck up 18-20 ounces on one flight. Of $20 gallon nitro fuel. I could even forgive its drinking habit, but no matter what you do, a certain amount of oil residue is going to get on the plane, and even living down here on the Gulf Coast where it is usually nice and warm, cleaning that crud off the plane and watching how it eventually ruins the Monokote on a nice airframe is disheartening. I can only imagine trying to clean it off a half frozen plane out in the cold. A well broken in gas engine will hardly leave any oil residue to clean off the plane, and it is much easier to deal with than castor or other methanol compatable oils.
For ultimate simplicity a magneto G26 would be hard to beat on the Stearman. With the right prop I have seen them fly very well, and unless you are trying to do some 3D with it I think you would like the combination. Here's the scenario: Fill up the 12 ounce tank. You don't need any more than that for 15-20 minutes of flight time. Switch off, choke engine a few cranks to draw in the fuel. Switch on, throttle set to two clicks above idle. Choke off, and a few flips of the prop and its off and running. Or if you prefer, a heavy duty electric starter will spin it up easily. No extra batteries, no glowplug connector, no muss, no fuss.