It sounds like you have had expert evaluation.
It is understandable you don't like what you've been told.
Give it some time.
I think you are going to be very frustrated trying to serve with a wrist brace.
I don't think there is going to be anything that really works.
Probably the closest is Brad Gilber's "Wrist Assist":http://www.activeforever.com/p-4680-...FYpQOgod9xcALQ
The problem is that ulnar deviation at the wrist during a serve occurs passively as a result of the powerful forces built up during the swing.
Wearing such a device is going to really change your serve, and would only provide a limited level of protection.
Did your hand surgeon mention that continued tennis playing is likely to result in "arthritic changes" along the bones in the wrist, with abnormal rubbing resulting in misshapen bones with ragged edges?
Once the "arthritic changes" occur, it is my understanding that successful surgery is much more unlikely.
And the potential for chronic everyday pain also goes up.