A couple more things to think about. Either of those MH's you linked to will become small inside in pretty short order------especially with a soon to be teenage girl.
Also, you need to have several thousand $$ in reserve for unexpected MH repairs. After traveling in our MH with just my DW for up to 2 months at a time (and being very lucky on lack of costly repairs), I would find a new job and move the family into a rental property in the new town using U-Haul equipment. Far less unknowns to worry about.
By the way, eventually you will want to resell that old MH---------and as the current owners are finding out, that isn't easy.