Years ago when I was visiting Don Shadow, Paulus Van den Berk was in from the Netherlands visiting nurseries and looking for new introductions (where better to look than Don). He told me about there Nursery and what got my attention the most was their line of topiary (imagine that). European nurseries are far ahead of what we are growing in the US. With tighter land availability they have been forced to develop growing techniques and equipment that in my opinion far exceed our own.
The availability is also much more interesting to me. All of the pleached, clipped and trained plant material I am always looking for is readily available in Europe. Here are some examples of what Van den Berk has available in their line or Topiary. I recommend you have a look at the website to see their full product line.