WHMCS is absolutely required for this project. Please bid only if your are very well versed in WHMCS modules, and scripting....
We need to create 4 Bundles using WHMCS and Cpanel, these packages as follows...
Bundle 1 - up to 5 websites, XX MB Storage, XX GB bandwidth
Bundle 2 - up to 5 websites, XX MB Storage, XX GB bandwidth
Bundle 3 - up to 10 websites, XX MB Storage, XX GB bandwidth
Bundle 4 - up to 20 websites, XX MB Storage, XX GB bandwidth
WHMCS needs to monitor each site as a whole Bundle and all sites are to share in the allotted Storage, Bandwidth and number of sites etc.
Scripts required as follows:
Monitor each bundle to force users to upgrade as each of the allotted requirements are exceeded, i.e. # of sites, Bandwidth or Storage.
Generate a new invoice allowing users to pay for the upgrade, with proration as needed
Change buttons within the admin area allowing customer viewing their account to go into the edit mode of our application
Based on these bundles and simple scripting required, we expect this to be a fast project. however, we will be needing ongoing changes within WHMCS, please also not if you are available for these tasks that will come up periodically from time to time.