Travel Trailer Size?

First of all, only you can decide how big or small of a trailer or 5th wheel you can live with. Although you sound like you both are very active but you may have a preference for a good kitchen area if you like to cook for yourselves. Also you may need a regular size queen size bed or even a king size if you are big and tall. If you order your unit you can specify if you would rather have 2 recliners or a sofa and either a dinette or table and chairs. I really don't think a half ton tow vehicle will handle much especially if you think you will be going through the mountains or high hills. We are not full timers but do spend most of the summers in ours for about 4 months. Our trailer is 34' long with 2 slide outs. I would not want less. We have a 3/4 ton truck and also would not want less. If I were you I would go to a big RV dealer and just look at all kinds and see what's out there.