IV's graphics weren't even all that, I mean they were an improvement but it had that oil painting effect and made it look shit. The trees looked shit as well. The level of detail was pretty cool imo. To answer your question, I don't think there is one available and even if there was, I don't think it would run on a FX 5200. ENBSeries is available for GTA3, but it doesn't even do that much. Here's a link to it anyways.