As stated previously this is for criminals only.
Primary weapon: OCA
Reasoning: This gun is unstoppable at close range and since many areas you fight in will be CQC this gun becomes a no-brainer. This player will probably complete most of the objectives with the other player covering him as this player will primarily be confined to low to mid range fighting.
Reasoning: This player will be doing most of the CQC fighting and will need another automatic weapon with a quick reload time if he runs out of ammo with the OCA or needs to take on multiple players at once.
Primary weapon: N-tec
Reasoning: This gun is accurate enough to take out enemies at medium range with ease and has the rate of fire to rip through enemies in CQC as well. This again is all about versatility when it comes to low numbers of players in a group. The N-tec simply works well at almost every distance.
Secondary weapon: Colby RSA(revolver)/S-AS
Reasoning: The Colby will be much better at mid to long range than the S-AS, but some users will want to rely on their N-tec only for mid-range and use the S-AS if someone comes close as the N-tec's reload speed is pretty slow. This spot is a toss up and comes down to opinion for the most part though I prefer the revolver and its three shot kill.
This setup allows your group to handle most situations easily and it doesn't hurt that these are the two best weapons currently in the game due to their versatility. I have a feeling that you will start to notice a pattern in these team setups until we get to the four person group :P.