Trip from Thailand to Yunnan Province China

We are US Citizens and will be traveling and staying in Chiang Mai and Chiang Rai, Thailand. We want to travel to Kunming, Yunnan province China. We do not want a tour. We want to drive and/or take a boat up the Mekong River. Maybe drive one way and take the boat back or vice versa.
I know we will have to drive through Laos if we go by car, and I believe that will require a Laotion driver and car. What about when we get to the border of China, will we then need a car & driver from China?
Does anyone know where I can get more info or am I going to have to research this when I get there? Any advice is appreciated. Again we don't want a tour nor do we want to fly. It is about the adventure getting to and from Kunming. Thank you for your help.

If you want to go from Laos to Kunming, I think you'll have trouble getting transport from the border. Maybe the best bet would be taking a bus. There's apparently a bus service from Louangphrabang to Kunming which opened late last year. This trip takes 22 hours (reading off the internet)

Just a side note, transportation services from Laos to Yunnan is known to cancel regularly due to low demand, what's running some time ago might not be running now. It is therefore better to get information locally I would think. Sorry for the lack to help but hopefully this will give you some hints.