Are the tops of your current drop bars wide enough for you? If they are, and you're sure you won't be usiing the drops anymore, why not just saw the drops off and flop them upside down? Just make sure to leave enough of the curve - which will now be sloping upward, as opposed to downward - to remount your current brake lever/shifters on. An easy way to use the bars you're not happy with to try out the bullhorn thing.
DanO