which external hard disc for music storage?

i want to store my music uncompressed on an external hard disc and play it via a dedicated ibook (or similar) and external dac through a high-end audio system. can anyone suggest what might be the best external hard disc? looks, price and size apart i guess quietness is key. are there other factors to consider? i have about 400Gb of music to store. are there any relative performance issues in filling a 500Gb disc 80% versus to half fill a 750Gb disc? i am currently considering a fanless LaCie.