You need to create action which will be generate Opportunity with products. All generation process should be divide on several steps. It is assumed that the number of stages can be increased and new ones added or the order of existing ones changed. Add the ability to undo changes when creating an Opportunity, i.e. do not commit data to the database until the final stage is completed.

List of necessarily steps

1. Account From. Case for showing this step - Org havn't such Account.
2. Opportunity form for fill data about opportunity.
3. Form for choosing pricebook.
4. Opportunity Products form for products creating.
5. Form for assign roles for choosen contacts