I'm about the same size as you. I walked into the Wiggy's factory and asked him what size. The owner looked at me and said "regular wide." He didn't get a yardstick out and measure me or anything though.
Mr. Wigutow seems to be a big proponent of going larger when in doubt. He says the bags...
I'll be the lone dissenter on this one. I had one for several years. Used it a great deal and never warmed up to it. I was glad to send it down the road. If you want canvas, go with a traditional canvas tent for the modularity and options. If you want a normal car camping tent, just get a nylon...