What gauge metal are you working with? You can make dies for any size you want. If you have a lot of hole to flare a steel die is the way to go. For just a few hole a hammer for makes more sense.
You can also make a die with a changeable center section so you can control depth of the recess and cut the hole after. Here is a picture of a die for making recesses for body mount bolts. The center is removable, you can make different height centers and have different size guide holes. The top die can also be changed to change the diameter of the recess a little.
Die design is the important part. You have to have a way to index the male and female dies and have a way to index it to the sheet. You can cut the hole first or after the flare is made. Just depends on what you are trying to do.