Over the years, I've used a lot of varied squash equipment. Some of it was good, and some of it just didn't work well for me. Here are most of the major squash companies I've come across, for squash racquets, protective eyewear, squash clothing, squash shoes, and squash balls. You can bet on these companies offering a full line of squash equipment, suitable for beginners to professionals (with varying costs to match that full range).
These are in alphabetical order, not in order of preference:

