Robin here
I just went to arttoday.com which is now
http://www.clipart.com and did a search for nurses under photos.
Can't really tell the diference between british or american I'm thinking.
If those are what you are looking for, it only cost $7.95 for a week and you can download all the photos you want.
They had a larger selection under clipart as well.
Hope this helps!
Robin R