WHMCS tax adaptation

I want to switch to WHMCS as a billing platform. Depending on the type of service that is delivered, I need to be able to invoice my customers with three different tax rates (full, reduced or tax exempt). WHMCS natively only support "tax or tax exempt". Some extra coding is needed. Please note that the tax rate can be different for each item on the invoice (each line can have a different rate). In your bid, quickly describe how you intend to tackle the problem. If this project goes well, further tweaking of our WHMCS installation will be awarded. Thanks for your bids !