Disc brakes are generally considered to have superior stopping power and mechanically minded people frequently make the conversion from rear drums to four-wheel discs, and I have NEVER known anyone to go from discs to drums. (As far as that conversion, there is a good bit that goes into it, and to me it is not worth the work, but I am lazy.)
I have had vehicles with rear drums and with 4-wheel disc, and personally I find it much easier to whip the disc brake caliper off of the rotor and change disc brake pads than I do to replace the shoes on a drum brake set up. But neither are rocket science, and if you find a good vehicle you want that has rear drums, I wouldn't let that be the factor that deters you.
And I will also say that brake shoes on drum brakes last longer than the pads on disc brakes.

If you're serious, take a trip to the liberry and check out a few books.

because i want to know more about automobiles.
The only poster who made Steve Lake wet his pants 4 times without ever breaking a sweat each of those times.
Wildmanwizard

Disc brakes and it's not even close.
Why do you ask?