Re: $330 AUD
I built a "football" for this exact purpose.
Its an old HP thin client running Debian in a Pelican case the size of a briefcase. Design didn't cut the case at all so its fully waterproof etc.
There's a small 2 port KVM in there, with a 15" viewsonic VGA LCD's guts fastened to the inside of the lid, and a small keyboard and mouse.
Case also holds server breakout cables for Cisco and HP and IBM (models I worked with at the time) and multiple blue cisco serial console cables
The thin client offers a NIC and a real serial port for consoles, and enough USB ports to console to ~8 other things via USB/serial cables.
Its all prewired for power so one wall plug does the whole case. No UPS or batteries though.
The idea was I can grab the football and a backpack full of spare cables and rock up to a data center, and fix many things straight off.
Long term plans included adding some kind of legs but ended up changing jobs before finding a good way to do this. Also thought about integrating a managed ethernet switch like a small juniper or cisco.