If you have to buy something new anyway (which it sounds like maybe you do), you might prefer something different than an iRiver. There are many decks in the sub-$200 range that are quite serviceable - the Tascam DR-07 and DR-08, among others - and are actually designed for recording without having to be Rockboxed.
Not knocking the iRiver generally and it's a fine choice if you already have one, but if you are buying something specifically for recording, I'd go for something else.