I would recommend the Outlast ones that show up at this part, I played with them and it was really fun, remember not to use SHIFT because it makes it too easy and unrealistic since it's the mechanic of the Half Life 2 suit. xD

With that said the npcs are (spoiler from the original outlast game) I believe patient 1 at the 2nd Floor the scene with the exit plates + beat down guard and Chris Walker after the explosion. Check outlast videos on youtube for a better view of where they should be located at.

I have yet to test out the map with other modded horror npcs...