748...lovely

Or, you could grab yourself a 900SS
You seem to have two criteria to consider,
a) you would prefer a Duke more than a CBR...
b) covering high milage in (relative) comfort.
I rode my 900SS down to Malaga last June and suffered no real discomfort at all. Obviously, as with any sports orientated bike, the arse tends to feel a little sorry for itself after about 400 miles but thatīs not soley a Ducati trait.
The SS was comfy, reliable (come rain or come shine) easily fast and torquey enough with the added bonus of an amazing soundtrack and looks. Say no more :wink:
If I compare the SS with the FZR600R I had before. I did the same trip on the Yam and the Duke was no less comfortable. The meaty midrange of the Duke though made it so easy to ride. On the open A roads, 3rd and 4th were all I needed most of the time whereas I was up and down the gearbox on the Yam like a madman. Great on a track maybe but became a little tiresome on a long haul.
Whether you chose to keep the SS after your touring is up to you. You might even prefer itīs less extreme tendencies.
Just my 10 pence worth
Hope you enjoy your trip. I canīt wait for my next tour!
Richie.