I will look in to the Blackburns again - they have probably improoved over the years...
Trouble is blackburn realised many years ago their profit is in volume not quality and the blackburns from 10 years ago would beat the blackburns of today...an ideal light rucksack/bag rack but not something I personaly would depend on for a tour..but each to their own but as I said earlier..it depends how much weight you are going to carry and I personally like the peace of mind of each piece of kit.
Another question is what bike I will use. I have several candidates and at the moment my Ritchey AscentComp is what I plan to use, but will be tested on a trial run this summer. But then I am thinking... traveling +3000km would a disc brake rigged bike be better, and should I go drop bar or flat bar? suspension seat or not? adjustable stem for making variations during the trip etc?
Look at most tourers and most will be v's or canti's..there are some of course with discs but in europe then spares for all kinds are plenty..so personal preference is your deciding factor. A good set of v's has always worked for me
For long runs and regular long runs I have a brooks b17 well broken in but I've always broken these in on short runs before a tour and padded shorts have worked better for me than a suspension seat..don't know why I don't get on with suspension posts, I just don't.
flats or drops...mountain bikes by build are not built to high speed over distance over a long period say such as a touring/racing bike. so the drops offer little benefit over flats on a mountain bike.That said it comes down to personal choice. I had drops on my thorn and couldn't get on with them but flat bar'd it and all was well in the world. Mine was a thorn sherpa world tour spec and not a bad bike at the price if this is going to be the first of many tours
as to adjustable stem..I left the post uncut and used spacers to vary the bar height dependent on the terrain and how I felt on the day but most of the time i left it pretty high for a more relaxed ride