A designed music dowload store online.

This website is targeted to a niche audience and further details will be given to the interested party. For now I am just trying to discribe the main technical features. A music download store for which the visiter will pay per track or compleat album to be download. This will be the main section but the website will also have relevant information about the artist and music.
In the other side I will also want my artists clients to have a personal account where they can oupload unlimited number of tracks; pay for the service and know how much they have in their account.