SHSH blobs are useless on the 4S and 5 at the moment. So once you update to iOS 7 beta, if you want to downgrade, your only option is iOS 6.1.4 and there is no way around it. No jailbreak of any kind as well on 6.1.3/6.1.4
And you have to open cydia and click TSS center to see if those are complete blobs. Tinyumbrella will download all blobs (both complete and incomplete ones)