There'a actually a huge selection for yoga gears for men although maybe not as "fashionable" as those yoga pants and crop tops catered for women. Also most men are not really that picky when it comes to sports wear, as long as its breathable and comfy they're good to go, or maybe most men I encounter with are not as picky as women
Some shops that sells men's yoga clothing are AloYoga.com, TheUpsideShop.com, even big brands like Old Navy has a section for men's yoga clothing. Another option is instagram and Facebook, there are a lot of online seller in that platform.