I'm sure, if they are in stock, KT parts dept would sell you one outright. The parts list I have (a couple years old) shows $110 for a chromed P3AT slide. I have heard of them doing upgrades (swap blued for chrome) for $75 although it may depend upon availability at any given time. You'd have to check with customer svc.
KT hard chrome is a matt finish. It is not shiny like a chromed bumper or something. It is aesthetically pleasing but it's greatest benefit is resistance to corrosion. Some also think it is a slicker finish that runs better due to less friction.
I don't know if that $75 hard chrome upgrade includes the barrels or not. You'd need to call KT.
For $75.00 you could have Ron Mahovsky do his "metalife" hard chrome. I am going to send him my slide and barrel. Ron has been doing this for about 30 years and I've had several guns done by him.