The control panel itself doesn't consume much system resources, however you need to pay attention to the following requirements when choosing a server:
Component Minimum Recommended
CPU 226 MHz more than 1 GHz
Cores 1 more than 2
RAM 768 MB more than 2 Gb
Disk space 10 Gb more than 50 Gb
http://doc.ispsystem.com/index.php/I...e_requirements