I use bullhorns on my main century and LD bike. I have an ordinary pair of Shimano aero levers on them the same as REC's blue bike. They work for me with caliper brakes.
If using disc brakes, I would check the amount of cable pull offered by the levers compared with that required to operate the brakes. You could experiment, and I am not sure, but the pull required to actuate disc brakes might be similar to cantis, just judging from my MTB (actuation of the brakes, as opposed to brake lever movement).
Last edited by Rowan; 04-18-08 at 04:24 PM.