Izerocoin (I0C) cap is $750k. Stable, been around for years, active dev, working and mobile responsive website. Updates coming soon see thread.

Kurrent (Kurt) cap is $250k, is the first zerocoin that uses X11 instead of Lyra2 algorithms to facilitate mining through GPU, and eliminate botnet control and hidden GPU miners. Also the first to introduce true random bonus blocks in zerocoin capable altcoin.