It's great to hear that you and your friends are planning a day trip to Waterford. There's lots to see and do in Ireland's oldest city
I think it would be a great idea to book a chauffeur or a small group tour company. This Travel Operators
page is a great resource that I recommend you check out.
There are a number of chauffeur companies in Ireland that may be able to assist with your plans. Here's a very handy Community post
where you'll find links to a number of chauffeur companies listed on our website that should be able to help with your private tour plans.
I hope this information will be helpful to you.