Integrate template existing wordpress website

I need a developer to integrate Stripe payment processor code into an existing wordpress website. The integration will be simple as there are only 2 items the customer can buy from the website. The site rents LED light fixtures for special events. Integration will have to allow for the following: • Customer adds desired quantity of rental lights to shopping cart. • Customer has a simple yes/no to add optional upgrade package to cart. • Only a $25 dollar charge is made (as a down payment) no matter the amount of lights added to cart. • Payment is made and customer information (Stripe token) is saved for future charge where the balance of the order will be placed before rental lights are sent to customer. That’s should be all that is needed. I am not a developer but know this will be easy to anyone who deals on a regular basis. I will need to know what type of accesses you will need in order to complete this project.