Ever try a Giant FCR?
Here's my two cents! At a reduced weight of 300 lbs I ride a Giant FCR4 that I've had for a lil over a year so far.The 700 X 28 tires that come with it are good. My LBS couldn't believe how long they have lasted. It's a flat bar fitness bike that thinks it's a roadie! The shifters are like a trigger shift, just push a button or lever. The rims are double wall with 32 spokes.Like I said, I was over 300 lbs and never have had a wheel problem. The bike tire if you wish can be replaced with a 700 X 30 Tandem bike tire which is heavier and thicker. Mine does real good. The FCR is $440 new.Other models vary! Hope this was a lil help?
Good luck and stay upright!