There's this new mod that came out a few weeks ago for Fallout 4 that has the dogs and Nightstalker from New Vegas.
Dogmeat's Many Faces New Vegas Canine Edition
https://www.nexusmods.com/fallout4/mods/38824
I thought I'd put it out there that, with the mod author's permission, these would be good replacers to use in NV. I don't have the skill nor knowledge to port these myself so to someone who does, this might be interesting to do.