I could be mistaken but "deep water turbo snail's" might easily translate into
LFS for "I can charge more money". Honestly though I do not believe there is such a thing but there are several different types of
turban spp. snails. It may just be a different sub.
Many types of snails will "prefer" different types of algaes as well as areas of the tank. Substrate, sand, glass and rock. The best solution
IME, is to get a combination of the ones that touch on all these areas so you are not solely relying on one type for all jobs. If I had the choice though, I would never bother with Astrea snails. You'll spend more time righting them than anything, although they are a great algae grazer. A good mix of cerith, nerite, nassarius and margarita would also be a good choice.
Cheers
Steve