|Yeah...you gotta be careful with that Ebay stuff ("thank you....come again")|
Accessing large caches of songs is simply gonna take a more computer-like device.
I just looked at that item....it is pretty cool...but again, consider that it only has Play, Previous, and Next buttons.
Even if you could connect it to a giant HD....what are you gonna do? What you are playing MP3 file #15....and you want to skip to file #85....are you gonna sit there and click 70 times to get to it? Sheesh.
Again....it's cool...but I would use it with a small flash drive....like maybe 128 mb...you could prolly find one for $10 or less....which would hold 25-30 songs.
That would be about my limit to have to scroll back and forth through. You can update your play list as desired by just taking the thumb drive to your computer.
Here's a link to a 128mb drive.
I think the site you posted sells them too, though.