Recommended Configuration to serve 50 clients

Hi,

I'm setting up a Plex Media Server on a Linux Machine for providing content to 50 clients in my neighbourhood of friends and family. The content is mainly movies with 1080p resolution, 5.1 channel audio and subtitles. 

I need to ensure that -  All 50 clients should be able to simultaneously stream media without lag. 

I have managed to setup the following - 

1. All the content will be stored on multiple QNAP 469 PR devices.

2. The network will be setup on a local intranet using ethernet technology.

Please help me with a suitable server configuration that can allow me to provide my content all my clients.