For PVE, a set of 5 TBS/Hundings/Night Mother's Gaze works really well. If you run trials, also use 5 piece Vicious Ophedian, then fill your remaining slots with what you have, preferably vMA weapons, but it's understandable if you can't. If you can't farm trials, then use 3 piece Agility Jewelry and 3 pieces of a set you like (2 spare pieces if you have vMA weapons, so you can use a monster helm set)

For PVP, you might want to go and be really bursty, so, obtain a set of Velidreth, and add in a 5 piece Viper set, and then throw in a set of Agility or Endurance Jewelry. If you have vMA weapons, take them. PVP has some really varied builds, because you really want to stack up stamina regen and weapon damage, but not crit, so make sure to find armor that provides high sustain.

PVE: 5 Viscous Ophidian 5 Twice Born Star or 5 Twice Born Star 5 vipers sting 2 velidreth.

PVP: Best set rn for a stamplar is 5 eternal hunt 5 vipers sting 2 velidreth.