Create Shopify partial payment option

We are looking for someone skilled in Shopify to do the following:- 1) enable a partial payment option for the customer. This is how it should work: We have a shopify site (not shopify plus). We have over 3000 products, all different prices. We want to do the following:- 1) In product page, show 2 options to the customer:- a) first option is the current default Full payment option b) 2nd option which you have to make is 10% payment option (which is equal to 10% of the product price) 2) If the customer selects the first option, then everything works as per normal as it is full payment option 3) if the customer selects the 2nd option, then the following things should happen a) in the checkout page, the product price that customer should pay should be 10% of product full price b) in the checkout pages, There should be a new line added to Product title: "Layaway Order" This is very simple project, but I understand that shopify does not allow to modify checkout page for Non Shopify Plus Stores. So you have to design it such, that if customer selects Partial payment (2nd option), the product price and product title should be modified while sending to checkout page I need a very skill and reliable shopify expert for this. I will not give you access to my site. You have to create a test site first by yourself and show me your code is working, then i will give you access to my site to move the code I have already tried other shopify available apps, and they do not meet my requirements. So do not suggest that i use one of those apps.