Re: Falcon XE
Door trims XD to XF will fit straight on as will front and rear seats. Can also fit the front buckets of any Ford XR-XF. All this stuff just bolts in. If you can get hold of an XF Fairmont Ghia interior, they look really good (IMHO), and are easy to fit.
If you are willing to do a bit more work, anything else seat wise can be used, but will require custom mounts/brackets and probably engineering approval over there. Same for steering columns, you can also get custom billet ones made up, or adapt just about anything but check with your rego engineers first!