True. SMBus/I2C has quite a large frequency range. The advantage of the 1-wire parts is that you can actually do it with 2 wires only and that would supply power and carry data. It's a bit slower when using parasitic power though.

The SMBus is quite important for the operation of your computer so don't fry it! At a minimum, the clock generator and RAM SPD EEPROMs are wired into it.

If you do use the SMBus then remember that most true SMBus interfaces don't like you hanging I2C devices off them. An example would be the Intel PIIX4 chipset. A lot of other chipsets implement the SMBus as an I2C bus so don't care. If you've got a I2C bus then your choice of chips is greatly increased.