I have 2 of these. I found that normally 25 feet is enough but I have the second when needed.
http://www.amazon.com/Camco-22783-Ta...ing+water+hose
Also, I roll my hoses into a Lowes five gallon bucket when they are not in use. The manner in which they are rolled allows only what is required to be unrolled while the remainder stays in the bucket and clean.