Rule of thumb. Add 1'6" to 2' to a model number to get a true LOA exterior.
JMO but new is not necessarily better unless you have 'new' money & are prepared for all the possible new unit glitches. There is nothing wrong with well taken care of used quality.
Be patient. Do your research for a few strong model possibilities & don't be swayed by a model that really is not what is wanted but is 'such a good deal'.
We started the hunt trying to stay at or under 32'. Bought a 34 model number, 35'10" pin to bumper, & have had relatively few problems for sites in SPs.
14 years later a model has not been seen that we like better. No itch.