Welcome from across the pond!
A simple rule of thumb I use is to NEVER buy new. The quality control of the RV industry in general is very poor. Some manufactures are worse than others. Winnebago is marginal at best.
We love our 2011 Itasca. It came with some QC problems that the original owner never addressed properly but, with that issue aside, we love our coach.
I don't know what type of RV adventures you like or how much room you are looking for. You know the limitations of RVing in Europe so, of course, you need to chose length first. Next is the list of things you want in the "house". Then comes the basement. I suggest avoiding rigs with the basement mounted on the slides. We had many issues with a Winnebago that was designed in that manner.
Here is a hard to find resource to keep handy. Winnebago has redesigned there website and things that were once very easy to find are now hidden. The old model brochures is now in an archive. https://winnebago.com/brochure-archive
. This is a good place to start looking for a used coach with the features you might be considering. I know many more questions will be coming our way as you begin to learn about Winnebago products.
Happy hunting and happy trails to come.