Agree.
In the end framing is a very personal thing and the final choice lies in the hands of you and the framer. He/she has the experience of looking at the original painting and has all the mat samples at hand for you to mix and match. Also there are the many frame moulding corners to mix and match with the painting and the mats. Another deciding factor is the availability of the mats and mouldings.
Another important factor is what are you willing to spend on the frame! All this can be a very confusing exercise for most. I know because I framed my own and my student's painting in SA for many years. Here in NZ I have been framing only my own.
At best, we can only give you suggestions. Not much help, eh!