Tang Planning

[Lampshade]

So i've recently set up my 135, everythings doing very well. I've picked up lots of coral recently, all doing well. Now time for the next phase, planning fish to add to the tank. I've gone far overkill on skimming, refugium, Biobeads, live rock, etc. Right now water tests have had 0 nitrates for awhile. I now need some bioload, haha.

Currently i have:
-Flame Hawkfish (currently tank dominant)
-yellow tail damsel
-2 osc. clowns

I'm Thinking of adding(not all but some):
- 2 to 3 tangs
- a schooling fish (looking at 5-6 chromis)
- a mandrin
- coral beauty or flame angel
- copperband butterfly

The biggest hurdle seems to be the tangs, what to add, and in what order. The rest should be fairly compatible from what i've seen. For tangs i've been thinking either:
-regal/scopas/kole
-yellow/regal
-scopas/kole/powder blue.

Anyone have any input on what works in their system? Obviously fish personalities are always different, and some will work while others not. I'm trying to avoid the "not".

Any input would be great, thanks.