While a 5500 or larger truck would be nice its not necessary. The F-450 can pull about 25,000# and still be a daily drive with a bed. These new trucks with super powerful engines, exhaust brakes, great trannys, tough frames, huge brakes are plenty capable.
The big issue with a Class 5 or 6 truck is insurance. Even if for private use unless farm plated many insurance companies want a CDL or at least a driving course completed. Why set yourself up for all that when then new modern 1 tons and the F-450 can do the job.
Heck, my 06 F-350 is rated to pull about 18,000# and does so with no issues and is nothing like the new GMC3500 or F-350 that are rated to pull about 22,000#. Its only 4 years old and the new stuff is so much better. Its amazing what they have done with these trucks.
Chris