I really want to make an non-retina iPad version, but I don't own an iPad 2/mini 1G, and I don't like the idea of releasing it without testing it out first. In fact, I can't even test on my mini 2G as it's activation locked on 7.1 beta 3 (I thought I'd removed that...). I might (sometime in the future) just release it and let people tell me if something looks wrong/doesn't work.
But for now, if you really want it on your iPad 2, I'd suggest using a tool such as GIMP to scale the iPad retina images down by half to 76x76 size, then renaming them to work with the theme (AppIcon76x76@2x.png would lose the @2x etc.). Icon names can also be found using a tool like AppInfo. You can just open up the theme folder using iFunbox/any other SSH app and move the icons to your computer and do what you want with them. With the theme installed, it's located in /Library/Themes/UltraFlat for iPad retina.theme/Bundles/
Sorry I can't be of any more help, but with a ton of icon requests to do plus porting it all over to the retina iPads, I just don't have time to work on much else.