If you have road bike that is comfortable, measure the points of contact (saddle nose, brake hoods, pedals at 3:00) and plot them on a graph, using the bottom bracket as [0,0]. You will then be able to compare the position to your current MTB setup. By using xy coordinates, you dont have to worry yourself with frame angles or size. Just swapping flats for bars may place the bars too far forward, and moving your saddle forward to compensate may upset the pedal position.
As an alternative to drop bars, you can fit butterfly bars. These give you a variety of positions but retain MTB style controls.
Most drop bar brake levers work OK with cantelevers (not well, just OK), but you need to tune the length of straddle cable carefully. Diacomp make a special long-pull lever for cantelevers and one for V brakes.
For shifters, you would have to use bar-ends or clamp on downtubes.