Use only one .esp, I recommend 'Complete'though it does require GRA to function. 'Basic' stays as close to the original as possible, and is not moddable. 'Moddable', well, is moddable. Comes with three weapon mods; an extended magazine, a scope and a suppressor.

Credits:

Models and textures: Toasty Fresh.

Obsidian and Bethesda for creating Fallout New Vegas.