It depends mostly on how much fuel you go through per year. Around here the fuel suppliers will not deliver less than 200 gallons at a time, so farm tanks are 250+ gallons, the one you linked is 525 gallons. In general you want to go through at least one tankful per year, else your fuel will end up getting stale, have issues with water due to condensation, and algae growth due to the water. Also note that you will get whatever blend of diesel is currently being sold at the pump when your tank gets filled, so if you get it filled in the winter, you will get winter blend diesel, and if it is filled in the summer, summer blend diesel. This may or may not be a big issue depending on your climate and how quickly you go through fuel.
I see in your profile that you have a couple of compacts with about 30 HP in your profile. If you got a 250 gallon tank, which is the smallest widely used (at least around here), you will probably need to run your tractors for at a minimum 200 hours per year (and in typical usage, probably 300-400 hours/year) to empty the tank in a year.
You would need to buy a shutoff ball valve, filter/water separator, hose, nozzle, and a couple of padlocks- one for the fill cap and one for the ball valve.