All I can contribute is wait for Brave New World by Dracomies (New Vegas Redesigned 4).
and
New Vegas Redesigned 3 (NVR 3).
Completely revoicing 100s of NPCs from scratch while modifying models, textures, NPC appearances and adding new questlines and dialogue. New Vegas Redesigned 3 is a nice stop gap while waiting.
Oh and Solid Project. That mod introduces several new gameplay mechanics like sprinting, jumping, first person animations, loot menu, item examination, etc. It got taken down the Nexus because the mod author was pissed for some reason, but it's still floating out there if you look.
I can help you get set up with some of the more obscure or overlooked mods that focus on immersion and new NPCs, including Outside Bets and 3DNPCs.