you don't move here for whitewater....
hill country is the best place nearby, with a few really good holes & waves at very high flows.
san marcos whitewater park has a decent wave http://www.americanwhitewater.org/content/River/detail/id/1830/
hidalgo falls may be OK - i have never been http://www.hidalgofalls.com/
surf kayaking can be good
mexico is still a long drive, but we are closer here than CO
you can meet some folks through whitewater club bcwc-l : Bayou City Whitewater Club
as far as CO hating texans, it is like anywhere, there are always a few jerks around but most people are nice. in southern CO they seem to get a warm welcome since they float most of the economy for the 'locals' (many of whom also came from out of state anyway)