Hi Grecko21, very good plan to go to Thailand and Laos!
We have been in Laos for 3 months. Rock climbing there is amazing! There are a few areas in Vang Vieng and a pretty new one in Thakhek. A couple of Germans have been in Thakhek in January 2010 and bolted in 50 routes in a range from 4 to 8a. Wonderful routes with tufas, sintering and also face climbing. There is a gigantic roof with 8 routes ranging from 6b+ to 8a+.
In Thakhek we liked it so much that we decided to stay and open a climbing camp. So we bolted in 20 more routes. The climbing camp is coming in November 2011. You can find more information and pictures on our website http://greenclimbershome.com
At the moment we are in Germany, but going back in September to bolt in more routes and help to build the bamboo huts.
We are going to public a climbing guide for Laos, but for now you can download the topo here for free: http://climbinglaos.com/downloads/laos-guidebook.PDF
Enjoy your stay! And if you have any questions you can contact me. Many greetings, Tanja