I spent several weeks in Laos in April and come across a wonderful tour guide by the name of Mana Phuang Boun.
Mana speaks excellent English and can organise a driver if you need one. The trip we did with him was from Vientiane-Plain of Jars-Luang Prabang, but he covers all of Laos. He used to be a Monk and prior to showing us around his beautiful country he had spent a week in a monastery, so it was really interesting to hear about those experiences.
Mana has a lovely, friendly manner and was fantastic at introducing us to locals we met along the way. He is very knowledgeable about the best places to stay and eat, and takes everything in his stride including changing our itinerary at the last minute to make better use of our time.
I spent a lot of time looking for tour guide recommendations before leaving home and couldn't find any, so hopefully this posting will be useful to others. Mana can be contacted on: firstname.lastname@example.org or phone +85 620 554 065 22. Happy to respond to personal messages if anyone wants further info.