We have found
http://www.zong.com/front/ - and decided to use this for switzerland, UK and germany. They will take aroung 40 percent of the cost of the sms as their commisssion. Probably will use another provider for US and far east (Our main target market)
It is quite easy and reasonably inexpensive to set up (the only large cost is to set a help number in
each country - or you can pay Zong to do this for you, which in my eyes is very expensive - Zong say that this is a "mandatory" requirement, but I am a little suspicious about this).
I will keep you posted once our website goes live and I have a chance to properly evaluate the Zong concepts and realities of the "percentage".
I looked at lots of other providers before I chose Zong, so I recommend anyone else looking for a similar service to start their search here and maybe save yourself some time.