Black headband vs Executioners hood
 

Which is the better choice for a monk?

Str is pretty easy to get, STA on the other hand...

I would say that if you are close to STR cap or want more hit points, go with the black headband. Otherwise exe hood.

What level is monk in question?

He's level 23, and I originally went with the exe hood, because I want to get my str up, I have a lot more agi/dex

You won't need the dex unless soloing with a tstaff or ada club or something. The agi will give you pretty minimal benefit compared to more Str and/or Hp. Just an FYI.

this is accurate.

to me, stat priority is hp>str=sta>dex

i dont worry about agility or AC at all.