Good halftone sets are hard to come across. Especially for Photoshop.
The main problem is that creating a remarkable halftone pack requires a shockingly large amount of work that most people aren't willing to invest.
To make a great pack, one that suits the needs of just about any situation, you can't just lay out a bunch of dots in Photoshop or get a texture and convert it to bitmap.
In the case of a halftone pack, one size does NOT fit all. That's why our Horrific Halftones Photoshop brush pack comes with a scary amount of halftones (but well organized so you don't lose your mind).