The scientific name of our native dogwood is Cornus florida. There are various cultivars available at nurseries.  For example, Gateway Garden Center in Hockessin lists Cornus florida 'Cherokee Princess' on their website of available plants.  This is a native tree that was selected for large blossoms, and so it is identified as a cultivar.  There are also red native dogwood cultivars.  Once again, these will have another name attached to Cornus florida.  Gateway lists Cornus florida 'Cherokee Brave' as a red native which they offer.

Maybe the name has been a stumbling block for your landscaper.  At any rate, there are definitely native dogwoods available in local nurseries.