https://realityripple.com/crypto_icons.html

Feel free to use or modify them to your own needs. Remember that fonts are important and not universal. Don't worry about ownership, I'm a public-domain type of guy.

ZCash is probably easiest to represent with ⓩ, ⓩ. If anyone wants me to CSS-ize a cryptocurrency, lemme know and I'll see what I can conjure up.