I had a client who asked me if he can be a reseller of my services (funny, the reseller of a reseller ...) anyway, I was not in the position of giving him a WHM because Im just a reseller and the WHM has information about servers, etc that the client could see adn discover Im not a 'real' host.
But, I answered him that he could be a reseller of my services by just purchasing a main account (a 'special' account for reseller & 'special' price) and then buying the same accounts I offer with a discount price.
That way, he is making money from me and Im making money from his frequent purchase.
It's important that you manage resellers with anonymous DNS, so if you are using your main domain as main hosting page & custom DNS, you may want to open a new account with another x domain to support your reseller with anonymity.
Also, there are some companies that offer Private Servers, some kind of managed servers (you can reboot, have full access to root, can add re-resellers to your reseller account, etc)
Tell me if you need further help or tips