Custom Shopping Cart (Wordpress)

Hello! looking to hire a WebDev who will be able to customize a shopping cart to communicate with a gaming API as the primary gateway for product redemption. Debit Card Payments will be used *only* to purchase more in-game points. The idea is a virtual arcade, where the games internal currency will be the currency (or tickets) that will be used to redeem a product from a catalog. --Step process-- // Account Creation Step 1. Player creates account on website. Website sends request to game_api server to initiate new player creation. game_server will send a 12 digit numer which will be players official login number. This number will be displayed in their membership profile page as well as total game_points available on their account. Step 2. Player purchases a quantity of points from game_Server. Request is sent to game_Server for 1-6 choices of point_quantity. Initiate Debit Card Transaction. If successful, add points to account. // From this point, player can now play freely. //Start Redemption process Step 1. Player browses and chooses item from catalog. Selects items for redemption. Step 2. Initiate point redemption. Send request to game_server. If player_points = > Products_total, then subtract products_total from player_points. Close connection to game_server. Else " Not enough points ". Step 3. player inputs shipping info. Finalizing process. The games api is written in PHP. Shopping cart that I'm using is the default shopping cart for Wordpress (Woo Cart). I'm willing to use whatever shopping cart is best and can provide best security.