Hi,
There are two sizes of earphone jacks used on portable audio equipment - 3.5mm and 2.5mm (the latter which is now being used on some of the smaller iPods/mp3 players). I'm 99% certain that yours will have a 3.5mm jack which is the standard on that type of radio (I have something similar) so type '3.5mm earphones' when you search that auction site for a suitable pair.
Alternatively if you live anywhere near a Richer Sounds store they sell them pretty cheaply and you can save yourself the p&p.
http://www.richersounds.com/productlist.php?cd a=productlist&sgroup=HEADPHONES&sort=price
http://www.richersounds.com/information.php?cd a=storefinder