The edge sander i've seen that you can make at home, uses self-made drums. Basically you stack home made discs onto a dowel, and glue them together. You make the discs out of 3/4" MDF, on the band saw. After gluing together on the dowel (whose OD should match the ID of the pillow block bearings you plan on getting... 1/2" or 5/8") it's recommended that you create a slight crown to help with tracking.
It's $10, but this plan from Shop Notes is worth it if you're going through with it. I would recommend checking your local libraries too. I've seen this issue at one of our local ones before, so it may cost you nothing to get if you can find it. Shop notes doesn't sell this back issue anymore. As far as I know.
You can also talk to some local shops (Is anything really "local" in Iowa? LOL! jk) and they can machine a part to exactly what you want.
I wish you the best of luck. This is a missin I am also on, so please, keep us updated.
The plans:
http://plansnow.com/dn3079.html