The most popular control panel are cPanel, and Plesk. Control panels generally have two types of licensing schemes, a Yearly license and a One time license. Yearly licenses allow you to pay by year and receive full Support and Software Upgrades during the one year period. The One Time license is generally 2 to 3 times the yearly cost and allows the Hosting company to use the software for life.
When running your hosting business for International customer, you need to look at the Multi language support options in your control panel. Another important feature from a control panel is ease of use. This will help your customer a lot. cPanel is the fastest control panel. The main page has icons makes it easier to access all functionality in minimum steps. Plesk is slower than cpanel.