Depends where you want to go. I have gone three times in colorado/utah on the colorado river and other rivers. (eldorado?)
These trips were for 3-4 days. You brought tents, and setup camp on the shore each night. The guides would cook for you, and etc. Usually around 15 people.
There was around 4 big boats (hold food, water, tents, luggage, the guides were on these) and around 10 duckies (for the people to have some fun down the rapids)
Dont remember the name, however I'm sure you could find it on google. Also- these rapids were not for the faint of heart, some really dangerous currents and drops, etc.