As an Internet exchange point, INX-ZA is not in the server hosting business. Many of the participants at our Internet exchange provide hosting and colocation services, and, fundamentally, INX-ZA does not compete with its participants.
Technically, while it may seem appealing to host a server at a central location, there is negligible difference in performance if the server is hosted on the network of a peering participant with a high-speed connection to the INX. You can find a list of INX participants here.
Realistically, you probably also want to host with an operator that is capable of providing you with the end-level support (for hosting and colocation) that you desire. You can do that more easily, with a network operator that has build and optimised their business for these operations. INX's business operations revolve around a low-touch environment that access to a high-speed distributed fabric; and not a team of engineers that do power supply replacments, or server reboots, or that measure of support.
We make exceptions for operators of critical Internet infrastructure, that benefit the users of the Internet in general. A good example of this would be anycast DNS server operators.
