Hardware Monitor/Sensor Add-on Boards?

DeeKayWon asks: "I'm going to be setting up an old 200MHz Pentium as a server in my house, and I'd like to be able to monitor things like the voltages, fan speeds and the CPU and chassis temperatures remotely using something like ksysguard. The problem is, the motherboard I have doesn't have a hardware monitoring chip. I would think that someone would be selling something like an ISA board with a sensor chip on it, but my search has been fruitless so far. Does such a beast exist?"