Considering all of your parameters, I would go with an OS 91 Surpass.

It will have plenty of power to do all you want. As far as cold weather goes, this is really a non-issue. 4-strokes work as well as 2-strokes when it's cold. In fact, they work better in the cold than when it's hot and humid.

My only reservation would be that the OS 91 would be marginal for 3-D, but since you don't want to do any 3-D, it seems to me like the perfect choice.

Plus the fact that you will have an outstanding 4-stroke for later projects down the road!