I would imagine it depends on what you do most on your PC.
Extra RAM is always handy - especially when you are doing lots of CPU/Memory intensive tasks (such as video and image editing etc.), and I would imagine that with the likes of WinXP 256MB of RAM will soon become the defacto standard (not necessarily the requirement, but probably users preference).
With the GF Pro you'll get higher 3D performance most of the time and good compatibility; but with KYROII you get the same amount of RAM, good 3D performance (although T&L titles may take a hammering with that CPU), possibly better 2D (dependant on what the GF Pro card you would choose), and better 3D IQ (certainly in 16bit, but many have been lauding the general quality of KYRO over others -
this is an example).
KYROII does seem to be having some issues with some game titles currently, but Videologic are listening and are releasing drivers every couple of weeks at the moment.
Tough choice. Personally I would go with the KYROII and 128Meg, but that?s because of the type of stuff I do most on my PC; your CPU makes the choice a little harder as well.
What videocard are you using currently?