The Legendary headliner for my 66 was top quality...including the small ear muffs they supplied. Perfect fit, seams well sewn, material is first quality, NO issues with fit or finish.
Also, their service was also amazingly comprehensive...including examining my original headliner which I shipped to them for certain detail clarifications.
I would not hesitate to use them again.
re: insulation. 66 has it, an asbestos-like fiber material glues to the sheet metal. Presume a 68 has something very similar. Many folks scrape it off and replace it with a variety of headliner insulating choices. See the headliner sticky for pictures, etc.