The F 550, if you are going to sand a lot. However if you only plan on having a 1.5 yard v-box i think the F 350 would be fine.
The AIC is a good option if you want to spend an extra 200 bucks.
Plow pre package
The F 550 would provide you with great hauling and towing abilities. It really comes down to if you want to spend the extra money or not. Also look at the capabilities of both models, and decide what capabilities ya need most. If you need a high payload and towing capablities all the time Go F 550, if these demands are only once and a while, go F 350.