Classic from what era? Seat tube angles wheelbases, and bottom bracket height gradually increased over time. I would consider a Coppi era Italian road bike "classic."

I agree that you should contact some custom builders, but rather than ask them to reproduce a ride quality of a particular era or country, I'd discuss what kind of riding you will do, whether and to what extent you will carry any gear, and how you want the bike to handle. And for the price of some stock ti frames you can get custom steel.

As for ti--it's a great material and I enjoyed my Airborne ti bikes a lot. My Carpe Diem was marketed as a cross/touring bike and my 58cm might have had parallel 72, but the chainstays were shortish and the bb was fairly high. Nice bike, but I've had many other steel bikes that handled better.