How to get ios6 back? I have a iPhone 5 with ios7 on it?

If I get a new phone from the apple shop can I just stick with ios6 or will it have ios7 already on it?

Yes but it is difficult. You have to download the iOS software from a website I'm not sure of the website name, just type in iOS 6 download and then once is downloaded go to itunes and connect your phone and hold the shift key while you click restore and it will pull up a window asking you to click the software you want to restore with. And sometimes the software is hard to find so I recommend saving the software to your desktop so when you look for it just click desktop and there it is.

I just re read your question and the answer is yes it will have iOS 7 already on it.