It's hard to improve too much on that Trio chip for 2D without getting anal and benchmarking a pile of cards against it on that particular system. Just a slightly gimped PCI implementation and you might find anything you can put in there only equals it, and theoretically good chipsets could have been put on indifferent boards.
It's not worth spending any money filling the RAM sockets, any socketed chips on dead hardware tend to get liberated right quick, but if you see some matching chips soldered down, on otherwise useless parts, there's this trick... SOJ chips, Small Outline J, with the curled over pins, usually have most of their electrical and mechanical connectivity in a fillet of solder on the outside of the pin. This means that you can take an Xacto knife or a boxcutter, and score down the line of the pins, aiming at a slight angle into the board. You should merely be carving through the solder. Score well on both sides, and take it lighter as you get closer to being through otherwise you'll bend the first and last pins in line... Then then it seems there's barely anything holding it, you can stick a flat screwdriver blade on it and twist... hopefully it pops off nicely.. it might pull off a pad or two... you can carefully scrape off any larger chunks with the tip of the knife, and then take a wire brush to it to clean it off well.... now hopefully you'll have an intact, thermally unstressed 40 Pin SOJ RAM chip you can fill up empty sockets with.
2017: Basement full of ancient PC stuff, starting to go through it. 2021: Still starting, heh, many setbacks. So what's this BitWrangler guy's deal ??? >>> Taming the pile, specs to target?