Plant Finder Tool Website
I happened to come across this neat website. You can enter what your search parameters are and it will then give you a list of what trees, shrubs, vines, grasses or perennials will fit your requirements. You enter your plant characteristics, landscape attributes, ornamental features and site conditions and this gives you your list. It is based on a private nurseries stock of plants or what they could get in for their customers so it is somewhat limited. You won't find it suggesting anything rare, unusual or really new, but it is a good place to go to get an idea for that spot you don't know what to do with.
Here is a link that might be useful: Carletonplace Nursery Plant Finder Tool