You should be able to choose a compressed but lossless format if you use a pc to play the music. Then you can use FLAC or WMA Lossless and the files will be much smaller.
Dumb file size question.
I just downloaded my first album from HD Tracks and was a bit shocked at the file size. I downloaded it at 96/24 in ALAC format. It is 1.26 GB! When I rip my CDs in ALAC format they are around 300 MB. What's up here? Is the HD Tracks file just uncompressed? Will iTunes compress it? Sorry for the stupidity just wasn't expecting to have to store and deal with files that large.