suggestions for an old computer

[Skunkwourk]

So my friend has an ecs k7sem 1.0pcb MB with a duron 900 in it, soon to be upgraded, possibly with an athlon xp 2100.

So if she gets the 2100 what would the best video card be that she could get without a bottleneck. Throw out your suggestions (try to keep thr price around 100).