Sounds like you want a 'porteur' style bike with a big front rack inclined back and a reduced-trail geometry for better handling under front load.

This is a pizza delivery bike in Paris:

http://www.cyclofiend.com/working/20...52-bb0207.html

For bigger loads, a bike with a platform behind the front wheel like a Bilenky cargo bike would be great

http://www.cyclofiend.com/working/20...rhard0206.html