From Nighthawks Shadowrun Wiki
Book review by Maclaine
This is one of the great works of literature that by rights should stand next to Tolkien and Thingy. It has all the guns you would ever want to buy, plus useful tools of the trade such as silencers, supressors, bipods, tripods, scopes and mufflers, for runners who like to accessorize. It has advice for which flak vest to wear, wether you're running away from Knight Errant or shopping for groceries.
My favourite section is called 'Heavy Weapons.' In it you will find a listing of all the best LM Gs, assult cannons, and missile launchers. It will tell you where to find a portable ATGM at an affordable price (never attempt to take down a drone-heavy compound without one). But if anyone knows where I can buy a circa 1975 M-60 belt-fed support weapon with a changable barrel, please call me on: 555-2997.
The Companion will also provide detailed instructions on custom designs (strictly for Hobbyists, IMHO), and a listing of all the groovy whizbangs you can load into your breeches, if you want to (though anything not beginning with 'EX-explosive' is a waste of money).
All in all, required reading for those of us dedicated to making this world an asshole free place, nine millimeters at a time.