I did the Montauk Century (100 miles) on my Specialized Sirrus LTD, with shorty carbon fiber bar ends on the flat bar. No problems whatsoever.
Lots of roadies will have you believe road drop bars are perfect for everybody (which is BS-- Every person is different), but try as I might I could never get comfortable on them. I find the flat bar + bar ends setup on my Sirrus to be far more comfortable than road drop bars.
Try out both. See what you are comfortable with.