Shopify Wallpaper Calculator

Description

We sell wallpapers on our website and what we want is:
Customers will select the wallpaper material they need from the shopifys own variants we have already set. The price of each material is listed as per meter square price.
Select Material:Non Woven - Price is £35 per meter squarePeel & Stick - Price is £39.99 per meter squarePremium Textile - Price is £44.99 per meter squareHeavy-Grade Textured - Price is £49.99 per meter square
Below this dropdown we need 2 field boxes WidthHeightcustomer should be able to enter there wall width and wall height here in cm or in inches and based on customer width and height and the material they selected the price total should be calculated.
We have shopify markets so this function should work with multicurrency without any issues, we do not want to use any ready made app, you will have to create the app of your own.
Important - we have a shopify paid theme which is Aurora and when we update this theme there should not be any issues with your calculator we do not want to contact you again and again once the job is complete.
We need the full job completed exactly as we have said.
You will be provided with the design file of the calculator which is pretty standard. Theme styles has to be maintained.
There should not be any issues with site microdata as we have google merchant center feeds in place your work should not cause any issues.
All this work is required to be implemented only on 1 product template which we call "wallpaper"our website has various product page templates and we do not want any issues to happen at all.
Please note the data customer fills in the width and height should be shown in cart sidebar, cart page and in checkout and in order emails
the price of materials we will be changing time to time in shopify variants and this should not cause any issues with the total price to be calculated.
We need a checkbox below length and width whcih would say "add extra 5% coverage" when this is checked than £15 should be added to the price total. customers should only be able to select this checkbox if they have entered the width and height only although this checkbox and text should be visible all the time. currency conversions should work correctly as i said we have markets.