Plans for servers like these usually differ in the number of processor cores, the amount of memory, the disk size and the network parameters. For one-off tests you can start with a small configuration. For continuous work it is better to take a server with headroom so the system does not run into its memory limit once you start several programs.
If you need to rent a VDS server with Windows 7, check in advance whether the version of the system you need can be installed, what resources the plan includes and whether you can move to a more powerful configuration if necessary. That matters especially if the server is being taken not for a couple of days but for regular work.
● Windows is available from the Brachium plan upwards — the lower plans are Linux only.