update!
Sorry for the delayed response. We got some rebates in the mail so I elected to get a new bike from a local shop. I have trouble getting shifters in tune, so I thought this would make sure I have a well-assembled in tune bike. I ended up with a Raleigh Talus 5.0! I tried a couple and this one seemed to just click! It's AMAZING how much a difference a well fitting bike can make. I'm at 15-20 miles/wk and climbing.
Thanks again for everyone's tips!