Take a look at bikes like the Bianchi Milano, Trek Pure, Trek Lime, Giant Suede, etc. that has a Shimano Nexus or Coasting hub. The Nexus hub is 3 or 8 speeds and you shift by turning the handgrip while the Coasting hub is an automatic transmission. There are also bikes that have just a 7-speed rear derailleur. I've ridden the Milano a few times and it's a lot of fun, looks cool, shifts VERY nicely, and did I mention how cool it looks? It uses the Nexus 8-speed rear hub.
Cruisers are comfortable but heavy and slow; the above bikes are also comfortable but faster because they have narrower tires.
My wife had the Trek 7100 that came with an adjustable stem. You can sit perfectly upright on the bike if you want. The Navigator is a comfort bike, meaning your feet can touch the ground without leaving the saddle and you sit upright. Trek even has an optional backrest for the saddle.