Of course, we don't know the pace of your itinerary nor if you are male or female. Carrying a fully loaded 26" suitcase is not funny for a man and can be outright punishing for a lady. So that's the first consideration I'd have.

There are many threads on hardside versus softside, easy enough to find.

Third consideration is wheels. They break, you're screwed. And they are likely to break on such a trip. No wheels, no cry - to paraphrase Bob Marley.

I'd consider a convertible backpack maximum carry-on size, e.g. Tom Bihn Aeronaut or similar. They don't look too much like a backpacker and hold enough stuff to go 8 days without washing.

In addition I'd bring a decent size personal item, say 35 linear inches, for your gadgetry and valuables. That one to be always with you.

The big bag will most likely already be above the 7-8kg carry-on limit some airlines have but at least you will be able to carry on for some flights. Arriving in Asia with your 26" hardshell filled with all the goodies still back in Europe is simply a frustrating experience.

In terms of protecting the contents; what's there to protect? Are you traveling with Ming Dynasty vases? If you loathe having the same clothes for three months, think about preparing a package of alternate clothes at home. Then, whenever you want to, have the package sent to your next stop. Your new clothes will be waiting for you there. You then send back the old clothes and start with a fresh set. This also works well should you need a wardrobe change due to different climates.

Safe travels,

Till