IPhone Factory Reset (Can I keep ios6)?

My iPhone is still running ios6 ( I don't like the ios7 icons) I want to Factory Reset it through iTunes,
My questions is will it automatically download and install ios7 or will it give me an option to stay with ios6?

The phone is jailbroken and I want to unjailbreak it.

If you're not 100% sure please say.

So if you want to factory reset it it ( with iTunes ) it will have the same iOS. So iOS 6 in your case. But it will ask you if i want to upgrade to the latest iOS ( iOS 7.0.4) and it will give you some options: Download Only, Download and Update and Close