As NoVaRT stated, start visiting large RV shows. You can go through some big Motor Homes, Travel Trailers, and 5th Wheels to see what you think. When we started initial planning we always thought a TT was the way to go. After going to several RV shows and visiting a couple dealers we soon discovered that we would need a large 5th wheel. Much also depends on your finances. If you are looking at a new diesel MH you can spend $500,000 pretty quickly depending on how big and fancy. If you are looking at a new 1-ton diesel PU and 38'-40' new 5th wheel you can spend anywhere from $140,000 to $200,000. Obviously if you start out with used rigs you will invest half of those figures.