For about $250 you could buy another pair of c1000s or different mics of about the same quality, plus you'd probably need a way to power them. Keep the c1000s, power them via the internal 9v battery option.
You can also power the AD20 with a simple 9V cell or you can make a battery cable with Radio Shack parts and power it with a Tekkeon or Wal Mart 9v external battery. For your application, I think the transistor cell will power the AD20 for a couple three hours so you probably don't really need an external cell but it's good for the landfill.
Same thing with the jb3, I think one of the internal cells will also power it for a at least 2 hours. What you really need is an optical cable to run from the AD20 to the jb3. These are getting pretty hard to find. It's a "toslink" connection on one end and a "mini" or "1/8" connection on the other. I've used these little connectors with some success.
http://tinyurl.com/2b7kca They will work if you're careful about making sure everything is connected and snug.
Edit: BTW - I ran almost this exact setup for a little while when I was just testing the taping waters. Run it for a while, spend as little as possible, decide what you like and don't like. If you're satisfied you'll be set and just start picking up little things. If you want to make a step up it's probably gonna take something closer to $750 or $1000 (IMO).