Sorry to take so long to respond to you but I was out of the office when your question came in. Growing cherries in Florence is problematic due to the high precipitation levels that you receive. Cherry fruit will crack if there is rain during the time that it is ripening (from yellow color through harvest). In addition, there is a disease, called bacterial canker, that can kill trees. Trees are infected during times of rain and when there is more rain there is a greater chance for infection to take place. Never prune your tree in the rain. In fact, there should be a minimum of 7 days of dry weather after you prune before the tree gets wet in order to reduce the potential for infection. This means that the safest time to prune the tree is during the dry months of summer. In years when the dry weather extends into September and October, September and early October will be you best months to prune.
As far as a fruit bearing cherry tree is concerned, all fruit bearing trees have white blossoms. I would recommend a variety called Lapins. It is self-fertile, meaning you only need one tree for pollination to take place and it has a little bit of resistance to both rain cracking and bacterial canker. If you want a somewhat smaller tree I would try to find it on a rootstock called MaxMa 14. This will produce a moderate size tree and may also help to impart some resistance to bacterial canker. If you want a full size tree, look for the rootstock Mazzard or better yet, Colt. Colt is the rootstock that is most resistance to bacterial canker, but it is hard to find. These will both grow large trees and they will take 5 years to begin to fruit. For a smaller tree try to find a rootstock called Gisela 12 or Krymsk 5 or Krymsk 6. Avoid Gisela 6 as this rootstock is very sensitive to bacterial canker. All of the other rootstocks besides Mazzard and Colt will cause the trees to produce fruit by the third year after planting.
There is a nursery in Wenatchee called Van Well that sells trees to both commercial growers and, I believe, homeowners. They seem to have the best availability of varieties and rootstcks.Here is a link to their website http://www.vanwell.net/. There are also many other nurseries where you can obtain high quality trees, including your local in town nurseries, but most of those trees will be marked full size tree (usually meaning Mazzard rootstock) or dwarf tree (usually meaning Gisela 5 rootstock, which I would not recommend) or semi-dwarf tree (usually meaning Gisela 6 rootstock, also not recommended).