The amount needed to host a Masternode is 100,000 ESS. Block reward has not been announced yet but 15% of the total supply of ESS Tokens are allocated to Block Rewards.

You can find more info here:

Token utility- https://essentia.one/Token_Utility_draft.pdf 

And if you have any questions please direct them
here:

https://t.me/essentiaonemasternodes