I recommend Synology NAS. I hear QNAP is better, but less polished and easy. I have a 1515+ which has no problem with transcoding. I suggest HGST NAS drives, 4TB and 6TB, because they have the best Mean-Time-To-Fail, but many people buy WD Reds because hey, it's redundant storage anyways, and Reds are a great value and not bad drives. If you only start with 2-3 drives, the whole thing will cost around $1,300.