Shopping Cart Integration App - Shopify, BigCommerce etc

Website Platform – Shopify Type of eCommerce Site – Custom Subscription Model Project Needed: I need a calendar to be integrated into my shopping cart that allows a customer to select multiple preferred delivery dates for different products on my custom subscription site, up to 12 orders/delivery dates a year. Since this is an annual subscription, I need these orders to be set as “reoccurring orders” as this will be a annual subscription online ecommerce site. For example: A parent subscribes to my store and would be offered the choice of selecting 2,4,6 dates a year, or a simple monthly subscription to receive their product or products. The customer would then need to select the desired dates within a calendar year in which they would like to receive their orders. Depending on which subscription they chose, this would be 2 times a year, 4 times a year, 6 times a year, or a monthly subscription for 12 times a year. In addition to selecting the date in which the customer would like to receive their orders, I also want to give the customer the opportunity to select which product they will receive on the desired dates. The 12X a year (monthly subscription) will not be eligible for this choice. It would be EXCELLENT, if there was a way for the customer to select 2,4,or 6 products from my site and then have the ability to drag and drop the specific orders into the calendar on the specific selected dates the customer wanted to receive that specific product order. From there, the customer could then go through the checkout, and during the checkout process, confirm the dates and products for those dates before payment processing. Again, this would be a one-time set up and would then be reoccurring on those specific dates until the customer cancelled their subscription. I would also need the ability for the customer to go back into their order at any time and change the selected dates or add additional dates to upgrade the subscription. Each customer has the ability to log into their own profile within the site, so each customer’s checkout would be unique to their individual orders. Current number of SKU’s – 45 SKUs, but needs the ability for me to add to the number of SKUs and add on product options.