Wow, this brings back memories. I did my route as a kid with my mountain bike. Used a bag during the week, a rack on Saturday (very thin paper). On Sunday the papers were a good two inches thick so I used a single speed with three wire baskets on it. I could only haul like 20 papers at a time, LOL. Good times!
Do some searching on the web, took me 5 seconds to find this one= 100# capacity.
http://www.bicycletrailers.com/Crooz...el-Trailer.pro