depends, they all breed easy, raising the fry is another story. The easiest are Erectus - thier fry hitch at birth and take bbs. They need nursery tanks and constant cleaning.
Feeding the lrg horses us pretty easy as long as you buy captive bred. They eat frozen mysis 2 to 3 times a day.
There are several threads here on raising dwarfs, you might look through those if you are interested in the tiny ones.
T