Hey ... not sure if you're familiar with it, but the NevoSL purports to allow remote control (w/metadata & album art) of a PC-based MP3 collection, directly on the remote.

not sure whether you were considering a remote or have already purchased one, but I have a NevoSL I'd purchased to eval - I'm beginning to realize it's not something we currently want to support, though, so if you're interested email me and you can have it at my cost.