While there are lots of cool choices for customization, The real question I had was deciding between the Caesar Revolver, and the Hockler Machine Pistol.
The Caesar looks to have a cylinder with 6 chambers, which would be typical. It also seems to have a really large caliber barrel. It also appears to just be modeled really thick and chunky, which makes me assume it is going to be a big, powerful sidearm, but possibly slow and definately lots of kick. The addition of exclusive silencers which are most likely available for use on all weapons, makes this an easy one to choose. Having a big silenced revolver should immediately appeal to Operatives. If this weapon is strong enough to take out an opponent with under 6 shots, it would be a very quick and stealthy way to take out opponents for light body type players.
Next up is the Hockler. This is clearly based off of the real world "Heckler and Koch Machine Pistol 7" more commonly known as simply the MP7. In real life, the MP7 is a modern sub-machine gun (its actually classified as a "personal defense weapon" which you could think of as a sub-sub-machine gun). It is designed for maximum portability and penetration foremost, with a very fast rate of fire. It is a very powerful weapon despite its size that can put holes through body armor, bulletproof windows, and even light plating. In games though, it tends to get the short end of the stick; often made into weak weapon with only its fire rate and lack of recoil to fall back on. The fact that it is actually spelled out "Machine pistol", as well as the fact that the Caesar is a sidearm, makes me curious if this will be in the game as a light weapon or a sidearm. It is a similar size to the revolver, and looks to be smaller than the Kross SMG in all of the clips, and Horse's compilation says that there are automatic pistols, so i am actually leaning towards the Hockler as a sidearm. The Greeneye Sight also comes with this bonus, which might be an interesting change of pace, but will most likely be fairly unremarkable when compared to all of the other scopes in the game.
Personally, the choice between the two weapons was a difficult one, so I ended up making the choice based on looks, and I really am not a fan of the psycho hood or tattoo. Besides, I plan on playing Security anyway. Depending on the strength of the Caesar though, it could very easily be the better choice.
As far as my opinions on the other two, purely cosmetic, bonuses - I'm not a fan. While I am a big follower of the Fallout franchise, I don't think the style meshes very well with Brink. The fallout art just won't look right when placed in a serious setting. The doom pack is just as unappealing to me. At first, I thought that security was able to wear UAC armor which would have been really cool, but upon closer inspection i realized they only get a t-shirt that is printed to look like UAC armor. Either way, a bunch of t-shirts and beanies don't compare to the prospect of new weapons.