Since you brought it up, I did the same with a diesel tank from on old reefer. 50 gal. Built a wood frame to hold it safely and I use my pallet forks to load it on the pickup. Added a pump, and when in the garage it sits on two HF dollies. 50 gal is 4-5 months of use for me. My supplier will not deliver less than 150 gallons so I understand why the OP may need/want a larger tank...especially if he uses it up quickly. Using off-road diesel ( $.50 a gallon savings) I will pay back my investment in about 2 years and not need to deal with those 5 gal jugs.
BTW, I have a 300 gallon tank but worry about the fuel going bad if stored that long. YMMV