NAS replacement for media files

Hi Guys. I am looking for a replacement for my Acer Easystore H340. I have a drive failure and think its time to purchase a 4 disk NAS. I currently have a mixture of 3X1TB and 1X3TB drives in the Acer. It will not read above 1TB of the 3TB drive...long story. Anyways I run plex throughout the house to a Mac Mini and an Apple TV 2 with only 720p content. The Acer has a 1.60 Atom processor and 2Gb of ram. I believe I should not be too worried about the NAS processor and ram since the devices that play my media do the transcoding. Correct me if I am wrong. I am leaning towards the Synology line and would have got the one at newegg last week but it was white (call me crazy). Do you guys have some recommendations of models I should look at? Not looking forward to moving the data off my Acer its over 3.5TB