Thanks to max.samael, this was initially for ispcp 1.0.7, and now it is time to try and make it work for i-MSCP.
I have purchased HostBill and have 30 days to see if I can make it work or not.
I will be porting this to i-MSCP 1.0.3 stable, as that is what I am currently running, and we can port it to 1.1.0 later, that will be the easier part, if anything needs to change.
I will probably have some questions but will reference the WHMCS module to get i-MSCP-side info...
Attached is the file...