Excellent, someone beat me to it! I made a forum account specifically to bring the monster mods on Nexus up here, I'm glad that I'm not the only one who likes them.
@ErrorNull there's at least one add-on by @khzmusik that adds Whisperer NPCs to NPCMod, but the only place I can find it is in the Mod Launcher (doesn't show up on his GitHub, but I'm not very good with Git so...). There's a few patches for NPCMod as well that add things like Loot Bags and progression/factions for the NPCs, but I don't think those should need any additional work.