Touring bikes tend to be one of a kind, they are not really mass produced.
Even the shops that specialise in touring bikes such as Spa Cycles of Harrogate,
Condor in London and your nearest local St Johns Street Cycles (Thorn) of Bridgewater only tend to stock a single supplier (themselves) and a the full range which is usually about 3 bikes.
What you need to look at, and test ride are the two 'benchmark' bikes, the Dawes Galaxy and the Surly Long Haul,
Personally I'd not buy either as brand new bikes, but I'd get a 2nd hand one, ride it for a few months, go on a tour with it, to then work out what I wanted in a touring bike.
You study other peoples bikes as you see them noting good bits and bad bits
You then go to someone like Spa, Condor or St Johns (there are a number of others) and get one of their 'standard' bikes made to your spec, or you go to one of the frame builders like Roberts, Mercian, Jackson, Yates (and many more) and have them make a bike for you.
Bottom line will not be much change from two grand by the time you have added the custom paint job, the panniers, the lights and all the trimmings. But done properly you'll have a bike for the rest of your life