For your strike package, you should chose Specialist. This is a knife only class and getting kills from a helicopter or stealth bomber doesn't exact stick with the class, plus specialist offers way more bonuses to help boost your class to the next level.
For the specialist bonuses, I like SitRep Pro, Scavenger Pro and Quickdraw Pro. You can use these in the order that they benefit you most. SitRep itself doesn't help you out much other than letting you know possible enemy locations based on where their equipment is deployed. SitRep Pro gives you a major advantage. it allows you to hear enemey footsteps louder. Also, you'll be able to hear enemy's who are using Dead Silence Pro. This gives you another tool in your bag for helping to locate the enemy.
You might be wondering why Scavenger Pro is on a class that doesn't use bullets. Unlike most of your tactical equipment, the throwing knife is actually replenished through Scavenger. This allows you to use and replensih your throwing knife multiple times, without having to track it down each time, saving you many deaths.
Quickdraw Pro allows you to recover from equipment usage faster. For this class, that means you can use the throwing knife faster. This is a huge benefit. I can't tell you how many times I've just finished knifing someone to notice a buddy behind him just out of knife range. A quick throwing knife can grant you this second kill instead of a death.