surfing and day to day stuff, there will be very little difference. gaming and anything that stress teh system will show the difference.
Run the sandra bench you have at all 3 speeds.
From my expereice the 110x8.5(935) is going to be the fastest, then the 9x105, then the 9.5x100. The biggest bottle neck in computers today is memory throughput.
At 110 fsb, thats 220 effective for the ev6 bus. pc 133 ram will also increase performace, especially if you go with the 8.5x110 as you will be able to better keep that 220 effective fsb fed with data to the cpu.