Need Experienced PHP Coder

I need an experienced PHP coder who is familiar with Joomla and Virtuemart to create a component that have the following function:

To be able to display 4 related products on the checkout page that would be (10% 20% or whatever percentage off).

Moving from PHP to marketplace forum.
You will need to provide more details about the project. More specifics on requirements, timelines and payment methods.