I can't offer any part number, but if you wish to switch to LED, you absolutely must use resistors with them. You must also pay attention to the polarity as LEDs will only work in one direction. You don't need to have the brightest bulbs you can find, but something in the 10,000 to 20,000mcd range would be quite acceptable (and you may find you need to tone down the brightness of the higher mcd bulbs).
Since you're not familiar with LEDs, I would suggest scanning through the various LED threads here to get an idea of how they work and what it takes to replace them. When you buy your LEDs, you need to write down the specs for that particular type -- forward voltage and current draw. Then you use those numbers to plug into an online calculator, along with if you are using the LEDs individually or in pairs, and that will give you the correct resistor to use so you don't blow up your LED. Once you have that, you may find you want to use an even larger resistor to dim the LEDs if they are too bright.