I noticed that you have a F-250. Before you even consider an RV check to see what the towing capacity is of the F-250. You could very easily purchase a left over from a previous year. Make a list of what you want to have in your 5er: Good insulation, LCD TV, type of tires (don't get anything made in China), Load Capacity, 50A, type of roof, type of slide mechanism, type of camping, decor. kitchen style, size of bed, etc. Then do your research.
I have a 2006 F-350 dually and it will tow 18,100 lbs. I have a 2012 Carriage Cameo that was one of the last off the assembly line before Carriage closed and we love it. We hope to full-time shortly too.
Good luck!