best deal
My advice, as a former rv sales weasel (sold Landmarks and Big Horns among others) is to fax your requirements to a number of dealers. Tell them what you are doing and that you want the best price upfront. You want an out the door price so you don't have any surprises at the end.
Markup on most RVs is in the 140% range, so if a rig is listed at 70k, then the dealer probably bought it for about 50k. The dealer has to make some money or they won't be there for you next year. You just don't want them to take a vacation to Tahiti on your purchase! If you get several dealers involved, you are more likely to get the best price.
Having said that, price isn't always the best way to shop. If you feel the need to have a great service provider, then paying a few bucks more for a rig might make it worth dealing with someone who you know has a great service department.
As a fulltimer, it doesn't matter to me where I get service as long as I get my rig fixed properly.