I use Pitbull3. Bars can be as simple or complex as you like. You can configure it to show only specific buffs/debuffs, which I use to keep track of certain procs {specifically seeing when I've spent Maelstrom Weapon or Art of War, or Eclipse procs when I ran a druid}. You can have the bars change color based on who has agro. You can monitor threat% with both a bar and a text readout.

For normal proc use, I use MikScrollingBattleText.

Dominos for bars, you can adjust the opacity and scale or hide them altogether.

DPS I don't bother with. Things die before I do, that's my main concern. If I want to see my numbers, I /combatlog and upload to World of Logs or something.

Mine's not a minimalist UI, but just a shot of some of those mods in action.