Hello Modo, I'm a Keighley lad exiled in That London
Sounds like a dream trip. I used to live in Munich and visited Austria a lot. By the time you get there you'll be as fit as a fiddle.
Just in case you feel the need... this is a new club near you (meets in Sutton I think).
http://www.southcraven.co.uk/
My brother (local roadie and MTBer) is a fan of Keith Lambert's LBS in Bingley.
Airedale is proper Mountain bike territory - I bet there are any number of hardly-used MTBs sitting in garages just waiting to be picked up for peanuts. If you're on a very tight budget, something like a steel, mid 90s rigid Specialized Rockhopper would make a decent, bombproof tourer with a a bit of fettling. Keep an eye on your local small ads (does the Keighley News/ Craven Herald still do them?) and ask around - you'll be amazed at what turns up!
(I've done a bit of touring on a steel MTB - Carlisle to Keighley on a Claud Butler Xanthos, and London to Brighton a couple of times. Didn't even bother to change to knobbly tyres - though I definitely would now!)