There are a few details in your request you are likely unaware of. If you want to store music in uncompressed format (or lossless), which is the best quality, it will take up quite a bit of space (300mb/CD lossless or 600mb/CD uncompressed). I don't think there are any services offering either format as downloads. You would have to rip them from original CD's yourself (very easy in iTunes). All the music download services offer some form of compression which is certainly NOT the "best quality format" you are looking for. As far as storing the music, it's best to store it on an external hard drive with lots of space rather than on the native hard drive to the laptop, at least if you plan on storing a library of any significant size in lossless or uncompressed formats. You will just end up clogging up your laptop if you try storing the music natively. I have a 320GB external drive that holds over 700 CD's currently. I'd recommend you assess how many CD's you plan on storing and how frequently you'll likely buy more, in order to determine the size of hard drive you'd need. As far as the operating system to implement the music, Mac has it all over PC, IMO, and is certainly very easy and instinctive to use. The remote function is a pretty recent innovation for the laptop world. A basic MacBook will include an AppleRemote and set you back $999. A 500gb external hard drive can be had for around $175 or much less if you want to risk some of the really cheap stuff (you need to backup anyway).
Marco
Marco