There's no need to travel gravel roads enroute to Alaska - unless you run into typical road repairs which you probably will. All you have to do is to drive slow and you'll have no problems. Millions have done it in all kinds of RVs.
Longterm - depending on your finances, it would be better to get a higher-end manufacturer in a used model than a cheaper one in a new one. Compare the construction (sidewalls, frame, roof, cabinetry) rather than the overall decorating 'look'. Compare the holding tank sizes. It's also best to find your RV first and then purchase a truck to haul it depending on the weight of the RV. Good luck!