If you're still looking at doing this style of UI.
1. It's ElvUI. The buttons are most likely 3 bars (left, mid and right sections). His frames are also part of ElvUI.
2. He's using AddOnSkins to embed his DPS meter (I might be mistaken, but looks like he is using Details).
3. Additional AddOns I can see on that video (for the few seconds I watched) is DBM and WeakAura's.
Apart from WeakAura's, that UI can be done it ElvUI in about 20-30 minutes.