Stuck upgrading iPhone 4 to iOS 6

My phone failed to install iOS 6 (latest i think it's 6.1.2). When it got to the last leg, it was stuck for hours (4+) on the same spot. Rebooting it did not work.

So I proceeded to do a clean recover to factory settings. That works. But when I try to get it to restore from my iCloud Backup, it is the same story, gets stuck pretty much at the same spot for hours. I absolutely need to get that backup back up (pun intended). What should I do? Suggestions?

Thanks.