Among:
Cryptonote;
Zero-knowdlege
Zerocoin protocolo (based in Zero-knowdlege)
Zcash
Zencash
A tecnical analisys please.
ZEC would be a fine option in this list and I am not sure this is cryptonight or cryptonote. If you want to know about cryptonight, this widely used in GPU mining people who mines with the simple mining pool like nanopool or even in nice hash too.
Other coins you have listed, I am totally zero knowledge about it. Zcash is the widely mining nowadays and in trading platform also this one of the major choice to hold the fund.
