There's no standard place to report TPI. You just have to look at the ads and manufacturers' websites.

There's also the amount of rubber on the sidewall and tread to consider. Some tires only have enough rubber on the sidewalls to stick the cords of the ply together. Those are called skinwalls. I had some 2.0" skinwall slicks but the tread was so thick I didn't find they felt like they were low resistance.