I've written a fast GPU-based vanity address generator, for finding a z-addr that matches a specific prefix or set of prefixes (with optional case-insensitivity). Ignoring the "zc", it can find a 6-character prefix in around 30 seconds on a GTX 1080 Ti, e.g.
All you need to do is install Rust, and then run
cargo install zcash-vanity.
The core is written in OpenCL for portability across GPU platforms, and the rest is written in Rust.
Happy vanity generating!