No and no. Wait for the ram to be priced under $30 for a 2x4gb kit. If you don't find any at that price, keep what you have. And no to a better heatsink if you're not overclocking. The stock amd heatsink is adequate.
4gb is enough for most things. If you are on a tight budget, don't add more. You also don't need to get a cooler because the stock one is designed to be sufficient for the un-overclocked cpu. Only buy a cooler if you plan on overclocking or if your cpu is overheating.