I had the same question a while back - see http://www.sjscycles.com/forum/topic.asp?TOPIC_ID=587
I still haven't bought a prop stand, having been rebuffed by everyone I asked about it! I will probably get one sooner or later.
The single arm ones that attach to the chain stay seem popular, but still not too stable (they also preclude attaching many trailers). I prefer the two-arm ones that attach behind the bottom bracket.
There are a few available in London from Velorution; see http://www.velorution.biz/?page_id=1045
. (I also love all the exotic continental utility bikes and the blog on this site!!!)