Wanderlust,  an excellent British travel magazine, has a site to help with  identifying British, Canadian, Australian,etc. companies which offer tours.    I've found it very useful in locating companies that offer more in-depth itineraries than US operators.  Perhaps it will be useful to you too.
www.mytripfinder.co.uk   
FYI - site for British,etc. adventure travel companies
        Message Submitted by Adventuregirl on Wed, 10/10/2012 - 08:25
      
    
    