I would be looking for a late model travel trailer (or even 5th wheel) from one of the premium manufacturers of "4 season" trailers like Northwood Manufacturing with a suitable tow vehicle. As stated previously, since you are going to be living in it nearly full time, a floor plan that you like and find livable is very important. Start looking at different floor plans, and picture yourself living in each one. Try standing at the stove and sink as if you were cooking. Sit at the dinette, try the shower, sit on the stool, etc. to see what will work for your life style. If this is your only home, you will need generous storage, which probably means a little bigger.
With a towable - as opposed to a self powered RV - you only have on engine and drive train to maintain, so normal day to day costs, as well as original purchase price, should be lower.
Start kicking some tires - you will begin to start getting ideas of what make sense to you ...