I would suggest subscribing to the tandem mailing list. Send an e mail to the following address with the word subscribe and your e mail address in the body of the message.
listserv@hobbes.ucsd.edu
If hubby isn't into biking I wouldn't spend big bucks. There's no reason you can't be the captain - it doesn't take any upper body strength- it's all in the legs. You may have trouble finding a non custom bike that fits you if he is bigger than you. Thom and I are about the same height and ride a small/small. It's really unlikely you'll find an off the shelf bike with a smaller captain compartment than stoker compartment. Generally the chick is expected to be in the back. We've talked about trading off, but I don't think Thom would be a very good stoker. I don't know anything about off road tandems, so I'd encourage you to post your questions to the listserver.
Good luck!
Veronica