Oh, the price options aren't done through any CCK field - they are just done with Ubercart. When you edit a product you can create an "Attribute" with different Options. Although if you're going to be calculating one product as several, that might be a bit harder.

I guess it's a question of do you want the mp3s, DVDs and Posters to be tied to ONE product? I think they should be separate, personally. But then you can link them using a "node reference" select list, again in CCK.

Here's a list of CCK modules I have installed (may not be using all of them):
Content
Content Copy
Date
Date Import
Fieldgroup
Image
Link
Node Reference
Number
Option Widgets
Text

I don't have time to link you to them all but I'm sure you can find them on drupal.org
User reference