I'm not familiar enough with the style of music to do any for you..
But as far as MIDI makers, they all produce basically the same sounds. Some of the better ones like Cakewalk or Anvil probably have some beat generators. Jazz++, which I use, has a random rhythm generator but that's not very reliable. Best to sequence by hand and ear.
Little known MIDI fact: General MIDI has a few different drum sets: standard, power, electronic, TR-808, brush, and orchestra. You can actually change the set in mid-song but it's tricky and not all players will recognize it.
Here is a simple drum machine program I got about 12 years ago. It can't save MIDI files but uses MIDI audio, so it's kinda useless except for practice.
By the way, did you want any semblance of Zelda music in your songs?