Can anyone suggest day wine tours or hired drivers for the Porto region ?
Trip Advisor is good for choosing day trips. I used CoolTour Oporto several years ago and was very pleased. They do small group tours. If you want a private tour, I would look at TA for those also.
I just took the Duoro River tour with the tour group mentioned above. Excellent! I had a great group and guide. Highly recommend it.