Sounds like this is just a Limited, not an XT, so the turbo wouldn't be a concern.With one owner it should be easy to verify the maintenance. Definitely ask about oil changes and new turbos. Maybe the turbo failed and now you have a brand new one, thats a plus, maybe it never failed so you'll have to pay attention to it.
There are many options for dash kits to install an aftermarket stereo, my 2005 came with one already installed, can't recall the brand of the kit but I know it cost less than $50And think about your stereo options. You are married to that head unit as it can't be swaped out for an aftermarket unit cheaply