Mellow And/or Whitewater Kayaking In Northern Thailand

Hello there,

I'll be in the Udon Thani/ Khon Kaen area and also later Chiang Mai and Rai very soon, around October 15-27. Aside from the Mae Taeng and Siam River Adventures, where are the best places near there (or in southern Laos?) where I can go to do some mellow river floating or even Class II to III whitewater kayaking or rafting?

I might have a little inflatable kayak with me so I can do a few safe/mellow things on my own with car shuttle help from my brother (he and his Thai wife teach in Khon Kaen).

Want to go hit the river with me? Have any good contacts or resources I might want to ask?

THANKS!

~ Shaun