It's impossible to say what might work for you unless you give them a try. Saddle fit is more complicated than that. I've never bought a saddle from Dover. Do they have a good trial or return policy? If so, order one or both and give them a try. Send them back if they don't work out.
Personally, I like to take a wither tracing of the horse. Then visit local tack shops and use the wither tracings to help narrow down the selection. You can sit in the saddles in the store to narrow sown your selection based on what might fit you as well.