Taking this at face value, why not go low-tec.

Use a DVD/CD linux distro with all the data on a usb drive.

Use ddns so you can physically move the location and equipment on a regular basis - hourly if required. Gauge what is needed by the perceived threat level.

Basically carry the system round in someone's pocket.

Use IRC channels to announce brief server uptimes.

In the event of problems, eat the USB drive!

Regards,
Steve