He had an absolutely beautiful tour last year and I went to see him at Cafe Oto where I was blown away by his playing. I just noticed on his site that he was thinking of a European tour so I got in touch with a UK label releasing his stuff and helping him out with tours and now I'm putting on a London date for him. I also said that I would look out for other dates around the country for him, and as this worked pretty well when I asked a similar question for Peter Broderick on here I thought there might be some likely promoters out there.
If you haven't heard of Steffen you should listen to him here http://www.myspace.com/steffenbashojunghans . he is simply a beautiful 6 string and 12 string guitarist, I always say he's just the best living guitarist in his "style" what with Fahey and Basho no being with us anymore but thats a massive generalisation of his approach and style of play.
If you're interested just drop me a line and I'll prod you in the right direction of what to do. Thanks.