I have found that your cpu will determine your fsb, in that with your given max voltage you will only ever be able to get the one overclocked speed.
You can set your multiplier low and have a high fsb, or set your fsb low and have your multiplier higher.
But you still will only get around the same overclocked value.
I went for fsb at 102,137 and a multiplier of 11 for my A900