Howdy,
I tried to list in the categories above, but didn't see an 'add thread' button - so...
For a rather comprehensive list of vendors, please see
http://www.ehrscope.com and scroll through the list of over 300 products.
Once there, you can filter them via 14 different filters, selecting only those that meet your criteria.
For a more robust matrix, you may visit
http://www.emrconsultant.com and have a custom analysis of your requirements. Once complete, the results will be provided to you in a Matrix, comparing your requirements with the features the various vendors acknowledge having.
Hope this helps.
Eric