Hi Wotan,
I assembled my system last week, still trying to figure out tweaks, other than OC'ing.
Asus CUSL2
C733@957
GF2 MX @190/195
Your biggest tweak will be a new vidcard, or OC'ing that tnt2. Like Staga said that is your bottleneck.
Staga, what are you using to cool that Gf2mx? I positioned a hole in the side of my case for a 80mm fan to blow on the Gf2mx, but dont have anything strapped to the actual card.