In 10 Days
Day 1 - Arriving at Tehran or Isfahan Airport (depending to the flight). It would be better to choose Turkish airline because its cheaper and has direct flight to Isfahan. If your group choose other flights we should pick them up in Tehran airport which is 4 hours drive to Isfahan. Depending on the time of arrival , In the way drive to Isfahan we can take them to some natural hot water springs for bath or show them some ancient palace in Kashan. They can accommodate in hotels (3 to 5 star) or even tent in specified areas for the first night.
 Day 2 - Breakfast in hotel or camp side and spend a day in Isfahan for sightseeing and city tours. Evening we will take them to Armand, have Dinner in the way (Naqhan) and reach to Julfa Rafting Camp beside the Armand river and sleep there.
 Day 3 - Start hiking or climb through the mountains (we choose the way according to the fitness and age of the group) to Doorak village which will takes about 4 hours and then lunch in the village. After lunch, walking along the river and fishing. Evening we will arrange tents beside the river and cook the fishes for them.
 Day 4 - Hiking to Dopolan bridge (about 4 hours) and prepare lunch over there and make them ready for rappel (56m height).After rappel we will have class 2 Rafting till evening. Then camp and dinner beside the river. 
 Day 5 & 6 - Use cars (Maybe Truck) for 45min , then go for Keredidcom Waterfall (110m and very beautiful) . For the local and young villagers it takes 8 hours to get there but for our group we should plan for 2 days trip and  return to Julfa Camp for dinner and sleep. 
  Day 7 - One day Rafting tour and after lunch go buy car to another camp and spend evening over there. We can arrange horse riding program if they like and sleep right there.
Day 8 - After breakfast, start one day trip to Absefid waterfall, its about 3h walk or we can also use horses to reach there and have lunch near waterfall. After lunch get back to camp, dinner and sleep.
Day 9 - Early morning wake up and go to Isfahan, breakfast in the way and lunch in Isfahan and then city tour till night. 
 Day 10 - Depending on the flight schedule we can have more time for city tour and at the end go to Isfahan or Tehran airport.

 All transports will be ours and every days include breakfast, lunch, dinner (very good quality Iranian meals), proper snacks and non alcohol drinks. 
  Its also possible to substitute some programs according to the guests interest, for example instead of spending 2 days for one of the waterfalls, they can spend 2 days in Mesr or Varzane desert which include hiking & walking on sand dune hills , camel riding ,Safari tours with 4WD cars accommodation in villages beside deserts or camp in the heart of desert and astronomy program and etc.

 The total expenses as I calculated (considered for 15 to 20 persons) is about 450.Euro for each, however there can be some changes because of fewer people or whatever extra or unexpected expenses but I hope you can get more idea to plan your trip better! 
The rental fee for a normal 4WD car with driver (I think best option for 6 persons) is from 150 to 250 US dollars regarding to model and etc. per day.
  I can calculate more accurate when I knew more details about your plan e.g. what grade of hotel or even tent for accommodation, how long you'll stay and what else that may effect the expenses.