I'm searching for a webshop which provides the following:

• The shop offers digital goods (like mp3)
• User can buy a voucher / gift card @Reseller (Or there is a code provided in the CD)
• User can enter his code @ webshop and gets the download (unregistered)
• User can enter his code @ webshop and download is added to his/her library (registered)

optional: Resellers can buy codes from the Webshop

I already tried prestashop as it looks quite nice. But it needs a lot of custom programming (and has a very strange voucher-system). Customer has to add the File into the basket and add the voucher at checkout. I want to skip that ;)

Is there a Webshop (Or CMS + Plugin) which provides the things I need? (it could also be a CMS with a Storage/Folder Plugin (like joomla + K2) and a possibility to activate downloads via unique Codes.)

Any ideas are highly appreciated :)

Thanks in advance.