I made a flow through worm bin out of a similar bin. I originally was sold the bin back in 1999 as a worm bin, but it was of the 'throw everything in the top and hope for the best' type.
Not sure how to post photos here, so it's pushed me to finally write the blog entry I've been promising to write and posted the pictures there.
As to getting your worms locally- if you can go and collect them, you'll not only save on postage, but you'll be able to see that the worms you get are good quality, and they'll spend a minimum of time out of bedding. Also, because you won't have to worry about postal weight, you can ask the guy to give you some of the medium they were living in, so they'll settle in quicker into your bin. (and some cocoons may come along for the ride!!)

Here is a link that might be useful: my blog