Linux (x86) binaries will work for any distribution of linux you chose from Spry. If you have a distro that supports RPM well you can use the RPM release that most closely matches your distro.

The link from SWSoft is a necessary step if you're upgrading past 4.0.

Feel free to use our support system at https://www.spry.com/support/myaccount/login.php if you have any specific questions about your VPS and don't want to give out details in the forum.