I use a 17" CRT ELO. Having to do it again, I would've went LCD instead. But it works fine...surprisingly fine. I'm by no means a tech guru, so I don't know if I got lucky, or they just seem to set themselves up. But I would go bigger if you can. The LCD's look bigger, so if you do go 15", at least go LCD. If I ever build version 2.0, that's what I'll be using.
I use EJukebox by Audiosoft. It is a pay software. I would also suggest trying a few out. But don't invest too much time mapping your MP3's to any one until you make the decision. Once you spend a few hours setting up songs, you're unlikely to move onto something else. EJukebox had a specific feature that really wasn't available on others at the time...I think it was displaying the playlist, but I'm not sure. It also has its share of shortcomings. Only you know what your vision is. It's a fun project though, maybe my favorite so far.