The really good VPS providers, allow out of band serial/VNC consoles so you can bring them up and configure prior to enabling networking.

The really really good ones allow you to install from your own images, in which case you can preconfigure firewall etc.

A lot of small providers offer truly "unmetered" bandwidth packages at low cost because for whatever reason they have contractually overprovisioned their bandwidth. They lose nothing by giving away unused bandwidth they have already paid for. Once they attract enough business to consume that bandwidth these deals go away.