Creating an API module for WHMCS

I have a reseller account with a web hosting company; they have provided me with an API key Secure Access Code (SAC). Unfortunately, they do not have a module for WHMCS. I need to create/integrate a module so I can use their API to create and manage packages from within my WHMCS. Note: there are many WHMCS API modules on the internet for other companies maybe you could modify and use? You must be an expert in WHMCS and you must send me details of what exactly you will do, please do not send me template proposal. Thanks