I think he is asking what's the point because that card is ancient and obsolete at this point, it really is time for an upgrade. Current integrated graphics are equal to or better than that card. Since this is a passively cooled card, the best thing you can do if you don't want to replace the card is to get a PCI Slot cooler or fan card, and mount it directly beneath the graphics card. I don't think you'll have luck finding an aftermarket cooling solution for it, the card has been out of production for ages, and it was fairly low end when it came out, most aftermarket coolers for GPUs are geared towards the larger higher end cards. It's generally assumed that owners of lower end cards aren't going to try to do extreme overclocking, so there is little demand for aftermarket coolers for those designs.
For a graphics card recommendation I would need to know more about your system. Motherboard, CPU, power supply, screen resolution, what games you intend to play. Generally speaking the gaming cards start at around $100, with something like the Radeon HD 6770, which would be a huge improvement over your current card. Even some of the sub $100 cards, like the Radeon HD 6670 would be a large jump over an x1300. However, without knowing your specs, I don't know if your CPU will hold that card back, whether your PSU can power it, or even if it will fit on your mainboard, for all I know your card could be AGP, in which case your upgrade options are quite limited.
Unfortunately I don't know how to detach the heatsink on that particular card. You might want to google it, and see if anyone has done a tutorial on that.