Audio & Video Player/Streamer

[808 Estate]

I am looking to rationalise and shrink my current Hi-Fi system to something a bit more modern and compact. Over the past few years, I have ripped all my CDs to FLAC, and copied all my tapes. I still have some vinyl, but not a lot. I will shortly be selling my CD player and tape decks. I also have approx 2000 movies and TV series recorded in 1080p. What I am looking for is a single box player/streamer that can replay both audio and video files. I am happy to accept an internal hard drive as long as it is user replacable, as it will need to be about 6TB in size. I am also OK with using an external NAS for storage if the player is merely a front end without storage. Is there anything out there that will handle both video and audio replay and provide decent quality, or will I be better off building a compact HTPC and setting it up with an android tablet to control it?

This also then brings up another question. Most audio streamers I have seen (as well as HTPCs) have built in volume controls. Is there a way to set the output permanently to line level (eg 0.75v), to feed an amplifier, or is it better to use the internal volume control and feed the output into active speakers? I have a decent Sansui amp and a pair of high end studio monitors, but I have also been listening to a pair of powered Adam studio monitors and do like their sound. I would be happy selling the Sansui and speakers for a good pair of actives (ATC/PMC etc), or keep the big monitors and get a better amp to drive them with.

With regard to video, I dont need surround sound or multi channel. At the most, it will be a 2.1 system (which would probably be easier to accomodate with active speakers), but I would prefer to err on the side of quality audio over everything else. Thanks.