Over-riding quotes

I want to be able to offer some products foc depending on the customer but include on the quote. I also want to be able to join some products together, not give an individual cost and do a bespoke price for that set of items without having to set each option up as a new product each time. Help please! We have a manufacturing business and sometimes we can be flexible on pricing dependent on the client and the requirements but I feel that this may not be possible?