Custom Order Status and Billing Frequency

Hi Guys,

I'm trying to implement WHMCS for some recurring marketing services and I would like to know if someone have previously achieved to add/change the default billing frequencies, for instance I need to bill one-time or weekly via PayPal.

Also, I would like to know if someone has created custom Order Statuses as I need those to provide a deeper detail on the process I sell.

Thanks in Advance,

UPDATE: I found out about the 'tblorderstatuses' table where I can define additional Order Statuses.