If you're talking about a program to download I don't know of any in particular that specializes in high quality mp3s.
Limewire is pretty good though in that you can do multiple searches at once, it checks the files to see if they are corrupted before downloads finish, and the program is supposed to be spyware free. Just go to limewire's homepage to download.
But the crappy part is that you'd probably need to preview each song to make sure it doesn't cut off or skip etc.
You'd pretty much just have to restrict your searches to certain bit rates e.g. avoid stuff less than 128.
If you want to make the mp3s I believe there's a program called Exact Audio Copy (EAC) that will take say a song from a CD and compress it to mp3 using a variable bit rate where if a part of the song is particularly complex the program ups the bit rate for that portion. The net result is a mp3 file that is larger than normal but still smaller than CD and the quality is better than the majority of mp3s out there.
