Watch out. I think what Biggs meant was that even if that article says that a 750 Duron will make 1GHz, it doesn't mean every single one will hit that speed. what you should do, just to make sure, is to play with the multipliers at the 100 FSB first. Bump the multiplier to 8x. If that works, and is stable, try 8.5, and so on, until you either a)reach 10x or b)reach the last multiplier setting at which the machine is stable. If the processor runs ok at 10x100 (as has been said before, you may have to up the voltage a little to make it stable), I would assume it would be safe to switch the FSB to 133 and let the thing boot at the original 7.5x. Just don't do the 7.5x133 as the first and only step - you may end up frying your CPU.
[EDIT]- Biggs beat me to it. Have to learn to type faster [/EDIT]