CODING REQUIRED FOR EXISTING SHOPIFY SITE (TORONTO)

My website is up and running. I need coding for a customization feature which would enable customers to type a personal message which will eventually be placed on my product. The customer's text must be within a designated range of characters. Ideally, the customer would be able to adjust the type size by increments and kern to fit a fixed position. 1. Customer clicks on the item they want to customize. 2. The locations where text can be applied are numbered on the product they chose to customize. There is text already positioned in the numbered areas. 3. Customer choses one of 3 options: i)Keep existing text ii)Delete existing text and leave area blank iii) Delete existing text and type their own text in the box below. Text must be between 90-140 characters. (This varies depending on the location) Customer can change the size and kerning with the buttons on the side for optimum placement. 4. The type box automatically keeps count of the number of characters used and informs the customer if there are too few to too many. Customer has the option of adding from a selection of graphic icons to increase character count. I have the supporting images completed. -Applicant must have experience coding for Shopify sites Thank you