In the interest of first things first, you have to decide what it is you want to change exactly; the rise, the pullback, the width, the diameter, etc. Some of the larger diameter bars require their own clamp which cost nearly as much as the bar themselves.
After deciding what changes you need to make, then you can investigate the various manufacturers to see which have the desired features for your particular ride.
WANT TO KEEP YOUR RIDING AREAS OPEN? JOIN THE BLUE RIBBON COALITION ONLINE @ www.sharetrails.org