No custom bikes are never done! I would go with the 6 over if you are going to do an extended fork. I would also put a fork brace on it. I dont like how much the stock forks flex when they are extended. I brace will help calm down the front end a little bit. Keep in mind it will make the steering a little "heavier" because of the increased rake. 6 over is a better compromise as far as handling goes.
I would cut the fender just behind the seat leaving enough to give it a little bit of a radius.
Weather is no good here either, already had one blizzard with around 20" of snow and 6 to 8ft drifts. Still get a nice day or two in here and there through out the winter though that can break out the bike for a short ride.