The Caesar and the hoker SMG are they unique guns or just skins, the other pre-order bonuses its written that they are skins but those it isnt written, so yea what are they?

They are indeed, their own guns. Not skins

The DOOM and Fallout packs are only skins
The Spec-ops and The Psycho packs are unique guns.

they SEEM to be new weapons, but they could just as easily be skins for the Tampa SMG and the revolver that are in the game.

Well either way Im gonna try and get the Psycho Pack (For the silencers)

I'm inclined to say they will be slightly different from the similar weapons already in the game.

For example I guess the MP7 will only hold 20 rounds instead of 30 for the MP9, but be slightly more accurate.
For the Revolver, the pre-order one will probably fire slower but cause more damage per shot.

Sure sounds strange that two packs gets two whole NEW WEAPONS, and not just NEW SKINS for already existing weapons.

I've never liked this ''pre-order here, get this, pre-order there, get that'' thing :l

Just as long as it isn't game breaking i would be ok with the pre-order stuff. like with the 20 rounds instead of 30 sounds fair for a slight damage increase. I pre-ordered on steam over x-mas cause the dude looked awesome. but i also wanted the psycho pack but o well

Well the Pre-order packs are created by Splash Damage. So they wouldn't do anything that would break the game.