I'm not a big fan of paddle style holsters. I used one from Blade-tech for my Ruger GPNY .38spl in the mid 2000s. I'd buy a solid belt loop style.
Popular brands include the Galco, Milt Sparks, Safariland, COM Holsters, HighNoon Holsters, Bianchi, Kramer Leather, SERPA/Blackhawk.
I agree. Paddle holsters are thicker due to their design and harder to conceal in my experience.
I'd also suggest looking at an OWB belt loop holster. I prefer leather and both Galco and Bianchi are well made holsters that won't break the bank.
Using a well made leather holster will provide enough security that you don't need the extra security of a thumb break. I understand when you first tart carrying, a thumb break seems like a great idea but in practice, you really don't need one.