Web activities menu

The requirement is to create on web application (the software used is flexible) which to allow potential customer to select from a list of activities and create a schedule. Each activity has as characteristics: short description, price in euro, duration in hours, day or night maximum number of people.? ? The users will be asked to input the number of people to attend the activities, the number of days, the number of nights, a budget ( a minimum budget should be calculated with a formula of number of people * minimum budget per person). After the input a list of activities that have lower price, lower duration? and lower number of participants for the number of people and days/? nights introduced should be displayed. After the user selects (mark a check box) one activity the list should be refreshed containing the selected activities and a recalculation for remaining possible activities from taking budget and time constraint. At the moment the budget or the time duration is exhausted that a final list with the activities selected, duration and price should be displayed. The user should select confirmation or restart of the process. After confirmation the schedule should be sent to site administrator by email and to the user to a specified email. The price for each activity should not be visible for the user, only a total price for the list should be shown. The activities and the minimum budget per person should be? customizable (possible to update)? by the site administrator.