Here's an example how newer driver versions have a negative impact on performance, these are some 3dmark99 scores on a K6-2+ at 600 MHz:
Geforce 3 21.83: 3525
Geforce 3 7.76: 4453
Voodoo 3: 3615
I believe Geforce 3 is the fastest card that still supports driver 7.76, Geforce 4 already needs 29.xx. You absolutely don't need a GF3 though, a Geforce 2 MX is also very good and it would reach around 3800 points here.
Regarding FSB overclocking, you have to remember that you need to disable the external cache because this is what mostly limits the overclocking stability. Few boards can reach FSB speeds of 110 or more with the cache enabled. And when you disable the cache, you lose quite a bit of performance. The difference between FSB 100 with cache enabled and FSB 133 with cache disabled isn't very large. If you can run it with the cache enabled at 105 or 110 MHz that's pretty good.
Here are some benchmarks to see the impact:
gf3, fsb100, 600mhz, ext. cache on: 3dmark99 3360
gf3, fsb133, 600mhz, ext. cache off: 3dmark99 3525
gf3, fsb133, 600mhz, ext. cache on: 3dmark99 3976
So with the FSB at 110 it would match or even surpass FSB 133 with disabled cache. This is on a VIA board, I don't know how an ALi board would behave.