You can read all about the event - and do some window shopping too - at the events website Hair Fair │July 16th - 31st. (The website also provides SLurls to each of the stores participating, for easy access.) There are also additional sims for cam shopping.
Judging by the website there actually seems to be a fair amount of hairs for men, not the usual 1,5-2% hidden away somewhere undetectable.
Happy hunting!
