Best video card update?

[David G. Maloney]

Got the Mac edition of Links, championship edition for my son only to find
out that the ATI 128 rage pro video card in my 450 cube is not supported by
open GL in OS 10.2.3.  ( nor is it supported by ATI).

The program is pretty much useless unless I can upgrade the video card.
Does anyone know if the geForce 2 MX is better than the ATI rage pro or
should I try the geForce 3 (I assume with a fan)?

Will both of these fit in without modification?

I would like advice from some of the gamers out there.

Lastly, I have not been able to find any of these to be had....

Thanks in advance,

David