I'd go tubulars.

The bike is not a workhorse so wear won't be a big issue.

Don't worry about flats. I carry sealant for small punctures and a cheapo Yellow Jersey spare to get home for large punctures. It is easier to swap tires on the road than it is to swap inner tubes. I will write that again for anyone who missed it, it is easier to swap tires on the road than it is to swap inner tubes.

The only bad thing about tubulars is the cost of the tires. I'll need to disagree with some in that I don't see the point of using a cheap tubular. They are no better than a clincher. But as you move into the expensive tubulars, the difference between them and any cheap tubular or expensive clincher is apparent, they are just better. And you really need (I think) a minimum of 25mm. A 23mm is too hard, might as well use a clincher.

If you look long and hard enough, you can find a 25mm Veloflex Roubaix for $75. Not cheap. Like butta.