But isn't there a normal lcd panel in the touch screen?
And could I do this without replacing the top half and just losse the touch screen function?

You can use a non-touch panel, but will need to replace the top half of the system - not just the screen. 

The hinges, bezel, wiring harness, back cover, etc. are specific to the screen type.  To swap one to the other, you need to replace all the parts above the keyboard.