All of those allow them to order direct to the lab. A few allow you to do orders yourself. Most have a free trial you could make use of, though I find you need that time simply to work out how the interface works.
Wordpress has loads of bolt ons that will do the job if you have a Wordpress site. Most of the bigger hosting companies also have ecommerce options available with he hosting.
Thanks guys...all i really need it to do is to display the images with an option to buy the unwatermarked file enabling them to use as they think fit. I will look at the suggestions I really don't want too much cost involved as its a charity organisation and my time is also freely given.