Can i choose which version of iOS to update my iPhone to?

Currently i'm on iOS 7.3 but this version has a lot of annoying bugs such as unable to update apps or facetime anyone, i want to update to 7.1.2 but i don't know if its possible to do so? If i press upgrade on iTunes it will update it to iOS8 which i don't want since its only an iPhone 4s and iOS8 is sluggish on it. If i download the firmware from the internet will the update be verified by apple or will it leave me without a working phone?

It will update to the new one that barley came out so everyone dosnt have an option to update whatever iOS sorry.