New Cavco: Standard Furnace or Gas Pack?

[LGJ]

We are getting ready to buy a new 1600 SF Cavco in Northern Arizona, where it gets quite cold with snow and ice during the winter. Question is do we go with the standard inside Intertherm furnace and add an outside A/C unit or delete the furnace and install an outside packaged gas furnace / air cond unit instead?

I know that one pro is that the outside packaged unit should be quieter, but will it be as reliable, durable, and efficient as the more traditional setup with furnace inside and a/c compressor outside? I know that at least one con is the additional cost. And I also wonder about the reliability of the Intertherm furnace compared to say a Carrier, or American Standard, which is probably what the outside unit would be. Anyone have any advice, thoughts, experience, etc? Thanks -- LGJ