I am not allow yet to place URLs (less then 10 posts), but just go to the "Ringtones, Themes and Wallpaper Discussion" and look at jibi's "sticky" named BlackBerry.alx - Edited Files for Packaged Theme Installation (4.1 & 4.2 ONLY)

Just make sure you get your current update, regardless of your carrier. For example, I use T-Mobile, but my current update is TIM (Italy) - 4.2.1.102/4.2.1.66, so that is the proper themes to download.