There are many many different ways to approach rain barrels.
After looking at lots of different systems and a little personal experience, I have developed a favorite.
60 gallon barrels are less expensive than 300 gallon totes even when you account for the water they hold. 60 gallon barrels can often be found for free and are easier to get in the car. 300 gallon barrels are a little easier to deal with in that you have less pluming, fewer spigots and potential leaks. We have some of each.