Re-Mortgage Calculator - Ajax/Javascript or WP EZ Form Calc

PLEASE CHECK BEFORE SUBMITTING A PROPOSAL: I need a Re-mortgage calculator that will integrate with a Wordpress SIte - I would prefer the calculator to be done using ez Form Calculator - functionally it will be the same as https://doddl.ie/new-calculator/ including the follow up page. HOWEVER, Ajax & Javascript is also OK.

+++ DEV SITE WITH FULLY LICENCES AND UPDATED EZ FORM PLUGIN INSTALLED AVAILABLE FOR DEVELOPMENT+++

It will go here: http://www.canweaffordit.com/remortgage/ so will need to follow the look of the Mortgage Calculator on the page here: http://www.canweaffordit.com/ (scroll down) which I have done with ez Form.

I have attached the Excel Calculation and the lookup table for the rates.

If you look at https://www.bonkers.ie/compare-mortgages/ you will see the same calculation:
Part 1
1. Joe has a house - he reckons it is worth about €500k (X)
2. Joe knows he still has €200k (Y) to pay, his interest rate is 4.95%, 20 year term so he pays €1341.40 pm (Z) (https://www.irishmortgage.com/mortgage-calculator/) - you have that calculator)

SO

Part 2
1. Check his LTV = Y/X % - in this example 50%
2. Look up the Variable rate for 50% LTV - eg 2.2%
3. Calculate his mortgage payment with this eg same as above but with 2.2% so €1,030.80 (NZ)

SO

Joe saves Z - NZ eg €310.60
You can show that over a year x 12

Final part is to apply all the available rates in a table ...

It needs to be done quickly ( I can do it myself, but I don't have the time!) - I want to find a good freelancer for similar work. I am behind on this project and need to catch up!

IN YOUR PROPOSAL PLEASE CONFIRM THAT YOU HAVE CHECKED THE REFERENCES AND ARE CONFIDENT YOU CAN DO THIS QUICKLY (and beautifully!) before submitting your proposal - if you don't confirm that you have checked I will not look at your proposal - fair enough? thanks, Alex