Supper 7 has 100FSB options...
some even have 133FSB...
but if you have a plain jane socket 7, 66, 75 and 83MHz FSB, you can always drop a AMD K6-2 or K6-III into the board.
The 2x multiplier acts as 6x so,400(6x66),450(6x75), and if you PCI bus cab take it, 500MHz(6x83)
What is the lowest Vcore that the board can take? As that is going to be your biggest problem. The K6-2/III CPUs are 2.2V CPU's (some were 2.4V)....
I have nevre run one at 2.8V, but i have had no problems running them at 2.6V....
SO hopefully you can lower you Vcore past 2.8V.... But that should still work with good cooling