I had a simiral situation. I used. Cat6 shilded cable inside pvc pipe buried under ground. It was pretty easy to run ran from a nic on a server (ipcop) to a switch in another building. Worked like a charm and retained the speed. Then again I didn't have a budget. Set it for my neighbors.
Gateway E-4200 (all original hardware except power supply fan and NICS)
Pentium II (Deschutes)
3 x 3Com 3c905 100BaseTX [Boomerang] (Red+Green+Blue)
Running transparent proxy, net-traffic (bandwidth counter), hddtemp, mbmon graphs, update accelerator.
I do not run Snort IDS because my...