If you want to do it right, this about covers it;
There is no barrel vise per say for M16 assembly, there are barrel vise clamps and you are better off using a receiver vise clamp rather than barrel clamps for installing a barrel.
Barrel clamps work well for installing flash hiders and muzzle brakes, that is all they are really good for.
Not shown are the good stout workbench and good quality bench vise and I didn't bother to put my barrel vise clamps in the picture either.
The pin punches used for M16/AR15 assembly are actually specialty roll pin punches, the have a teat on the end that fits the hole in a roll pin and helps prevent the punch from slipping off the roll pin and marring the surface finsih of the rifle as well as preventing the roll pin from splaying out during installation.
In addition to the punches, roll pin starter punches are also used, these are punches with a well on the end to hold the roll pin and these make it much, much simpler to start a roll pin into a through or blind hole.
There are some specialty tools in the picture that make installing the front pivot pin and A2 sights much simpler.
There is a center punch for staking things like the carrier key and collapsing stock assembly end plate to the castle nut.
There is a long shank screwdriver for the pistol grip and buttstock.
There are snap ring pliers for installing the split washer that holds the delta ring and weld spring in place.
Hammers, a barrel wrench, a collapsing stock removal wrench.
There is grease for lubing parts prior to actually assembling them and there are gages to make sure everything assembles within tolerence.
A good set of tools will set you back about $400.00