Personally, having had experience of a similar tandem (Bill Phillbrook with Mafac canti's) - i would not worry about the need for a drag brake with the ride you are anticipating - with <300m of climbing you will not be likely to overheat anything on the way down or face a situation where you had insufficient braking force. If you ever plan to do longer, steeper rides, then i would seriously consider upgrading the braking area - either a drag brake if you have the clearance (we couldn't as the rear spacing on our tandem was 130mm) or at least upgrade brake pads. BTW - we changed the hubs from 36h campag sheriff star to 36h shimano ultegra on open pro rims and the average speed increased by 1.5 mph.