Here is a more dual purpose worm that is getting popular
European Nightcrawlers
European Nightcrawlers (Eisenia Hortensis), Big Reds, Belgium Worms, Carolina Crawlers, or whichever name you prefer to call them, make good breeding stock for your worm farm and good composting worms for your compost heap.
Like the common red worm, the European Nightcrawlers make good composting worms for your compost heap, although they eat a little less and breed a little slower (approximately 1 egg capsule per week).
The European nightcrawler worm will grow longer (up to four or five inches) and fatter (about as thick as a pencil) than red wigglers but are still a perfect fit to your worm farm.
I am going to add these to my farm as soon as I can. I will just keep them in separate bins and try to sell some to the local bait shops. We are surrounded by great fishing lakes here.