Looking at buying a portable black tank - suggestions?

I used an 18 gallon tote and it was heavy when filled I wouldn't have wanted any larger. I had my MH parked at my sisters place for 10 weeks. about 150' from the sewer cleanout so I couldn't hook up directly to the line. I dumped black and gray every Saturday for 10 weeks, I had a 42 gallon black and 42 gallon gray. I usually made about 4-5 trips to dump the weeks worth of stuff. A real pain.