I found a nice tutorial about how to theme your product pages in Ubercart. In Ubercart it's easy to get basic product pages, but to make them look unique requires a bit more finesse.

Here's the post from the forum:

http://www.ubercart.org/forum/development/3868/nifty_products_tutorial_part_1

And while we're talking about themes, this seems to be a nice module for doing themes with CCK (which Ubercart uses):

To my eyes, the most promising open source e-Commerce platforms I've seen lately are Ubercart and Magento. We're actually currently using Ubercart here as I write this, for this very site! Ubercart is actually a module for Drupal (a powerful content managment system). Drupal has another e-Commerce module... Drupal e-Commerce (yes, not very imaginitive, I know), but it's not currently quite as full featured as Ubercart.