Check out Toursbylocals.com. We’ve used guides from this website in Toledo, Edinburgh, Dublin, Havana, Split, and Bruges to name just a few cities. On their website you can read about different tours and you can read profiles of various guides. You can then check their calendar to see if they are available for your dates. Their profile tells you if they have a car or use public transportation. When we found a match, we would email the guides with our wants and number of people and would work out an itinerary.
For example, when we were visiting Dublin off a cruise ship, we wanted to see Kilmainham Gaol, Guinness, St. Patrick’s, and the University grounds. He told us what order to visit and what time to book the different sights. He picked us up on time, and dropped us off at the designated time on the pier.
He made some suggestions which we worked into our day. The day went smoothly and we even had a lovely fish n chips lunch and time to do a little shopping. He was accurate with how long each sight would take to visit.
Another bonus is that the prices are on the website under each tour. You have an idea if they are affordable or too expensive and can keep searching.