All the very best of luck to you and your lady.
Being an Aussie I would say buy a motorhome rather than a caravan, but that could be an Aussie thing as I have a Volkswagon van
I am sure you will not regret it as you seem to be starting with the right attitude.
Who knows where you will be and what you will be doing in 5 years time.
Lifes big adventure, scary but to some irresistable.
I arrived in Britain/Europe 7 years ago with my backpack and my road racer and where I am at the moment and what I have done inbetween I could not have imagined and some things not always good but from those you learn.
As some one once told me:
Brave men dont live forever, cautious men dont live at all.
Carlsberg dont build Singlespeeds but if they did.......they would probably look just like mine.
I've spent half my life on bikes.........the other half I wasted