How to "make your own" high speed proxies (reserving ips)

I was speaking with a friend, and he mentioned a service using thousands of their own IP's. What I mean by this is: they had somehow reserved a setset of ip addresses, and were using those to issue http requests. Does anyone have any idea on how this is done? I'm curious as how to replicate the end result of a proxy, but without having to actually proxy through another server, rather just "send" a request from a server using a different ip address. For my purpose, I need speed, so I would rather issue http requests from without having to chain through another server, slowing it down.

A quick diagram of what I mean: the speed from the server to a website should not change, should not route through an external server.

VPS (a server) 
    -> sends a request using ip xxx.xxx.xxx.1
    -> sends a request using ip xxx.xxx.xxx.2
    -> sends a request using ip xxx.xxx.xxx.3
    -> sends a request using ip xxx.xxx.xxx.4

Edit: upon doing some research, I think what I need is a /48 subnet/network of ipv6 addresses. Can anyone confirm this? Also, does anyone know of any hosting providers that will accommodate this.

I appreciate all help, thank you all.