Need to know best audio format, player, and remote control for music for audiophile sound system

A very serious audiophile has the finest preamp, amps, CD player and speakers available.  They want to attach a music server and load the server with the finest digital audio recordings they can get, and select between orchestral and 'Pop' recordings stored on this server.  They would also like to listen to audiophile Internet radio (if such exists)

What's the best (of the best) format of music file available?
Since they will be playing digital files, will a regular NAS be suitable for storing the audio files?
What type of interface to their audio system should they use?
Which remote control system will run on an iPhone or iPad?
Are there highest possible "Internet Radio Stations"?
Links to audiophile websites will be appreciated.

Thanks.