I bought a Schwinn Solitaire from Walmart to make may 12 mile round trip commute each day. I upgraded the tires to Continental Sport Contact. I found these tubes work just fine:
http://www.amazon.com/gp/product/B00...ef=oss_product

I have not had any problems. The bike seems to work just fine. I couldn't justify spending a lot of money on a commuter before I knew if I would like it. IM not sure how it will hold up long term though.