PC vs NPC entry for Classed NPCs

[jrh18]

I have been trying to figure out the best way to create NPCs that I want to level up with the characters. These NPCs will have a class like a PC.
Option 1 is to create an NPC record and then add the stats and abilities for the character's class.
Option 2 is to make the NPC like a PC and then make them GM owned.

With an NPC I can calculate the CR I think based on the DM guide (new to making monsters). With a PC I am not sure how to calculate the CR, but I assume it is the same as an NPC.

Does anyone have any recommendations on which approach is better?

[Zacchaeus]

Option 2. Much easier, no maths required.

[Stitched]

Also easier to give a PC, that is "GM" owned, custom equipment.

[Myrdin Potter]

In general, the rules for NPC "foes" in 5e is a stat block like a monster. If you are trying to make a DM controlled character that interacts with the party, then option 2 seems easier.