However, I plan on only keeping the rig for maybe 48 months.
If you are concerned about finances purchase pre-owned. Find a coach that is four or five years old and you can get it for about 55-60 percent of new as it will have suffered extensive depreciation since new. Then you are financing a little more than half the new price and you can use your trade-in money to buy down equity or should you sell it outright the money could be used for other things. In the long run you can save a ton of money, get a relatively late model unit, and when you sell it you will not eat new coach depreciation.