WHMCS and Wordpress customize billing and invoice

Hello, I have an existing IT business and a website called OneChoiceIT.com. Our business is local at the moment and we have users calling us to resolve their IT issue. However, our service runs into issues generating invoices and receiving payments. We would like a billing system like WHMCS that would integrate with Wordpress I have on my webiste. PLEASE NOTE WHMCS WILL NOT USE ANY OF THE DOMAIN FEATURES OR HOSTING. WHMCS WILL NEED TO BE CUSTOMIZED AS LISTED BELOW. DOMAIN AND HOSTING ICONS AND INFORMATION NEEDS TO BE REMOVED The customer we'll be able to simply click "Submit payment" on the top our website. At the top of the page would be great. Once the user is on the page, we'll like them to submit their customer information. First Name Last Name Address Address 2 (OPTIONAL) Apartment, suite, floor, etc. City State/Province/Region Zip/Postal Code Phone Email Invoice number: - This is provided by the tech We would like a system where the IT tech we'll be able to create an invoice in WHMCS Example Invoice number: 123 (OR AN OPTION TO SELECT I DON"T HAVE AN INVOICE and choose a list of services). Service: Virus removal Price to charge customer: 45 Tax: Yes or no --------------- One time FIX: $34.99 Printer setup, Internet & WIFI ISSUES.. etc. Advanced system care: Virus removal, PC TUNE UP Once the technician submits the information into WHMCS the customer submits the billing details as listed above. In addition, the customer we'll go ahead and submit the invoice number the tech provided on the phone as well. (It is very important for the WHMCS to capture the billing details and invoice number for accounting purposes). In this way I'll be able to go in the WHMCS and look up this information. Next - This will take the customer to a check out page with the service listed and an option to pay by credit card, PayPal, Google Pay, Stripe, using a checking account. See attachments of examples what I'm looking for * Please note I would like an option where it we'll email the customer the invoice information as well using WHMCS & Please note I would an option where it will give you an option to download the invoice when the customer enters the invoice number and give you a description of the invoice * I would like an option where you wouldn't have to enter an invoice but you'll be able to check the list of services and it would automatically create the invoice for the customer. Please see the attachments for examples The last Freelancer failed on this project. I hope to find the right person this time to complete this as soon as possible. Please note this project WILL be completed on this project only. I am not going to create two projects as the other freelancer was requesting me to do. He asked me to create two projects which charges me fees and is against Freelacer TOS.