I doubt you'll find anyone selling ready to install seat covers, they'll have to be made by a local auto upholstery shop.
Acceleration will be leisurely by today's standards, but a car like that should be able to cruise nicely on the highway at 60mph (100km/h). When I was a teenager I worked for a guy who had a 1953 Pontiac station wagon; I used to drive it for running errands and had no issues, but it wouldn't have been suitable for Autobahn use.
