Combat Medic
Starts with: Pistols, Sub-Machine Guns, First Aid
Level 5: Adrenaline Boost
Level 10: Light Armor
Level 15: Nerve Gas
Level 20: Feild Clinic
Level 25: Shotguns
Level 30: Free Gas Mask
Level 35: Medium Armor

Commando
Starts with: Pistols, Assault Rifles, Toughness
Level 5: Medium Armor
Level 10: Heavy Weapons
Level 15: Grenadier
Level 20: Ballistic Shield
Level 25: Heavy Armor
Level 30: Enhanced Recovery
Level 35: Recoil Control

Engineer
Starts with: Pistols, Shotguns, Electronic Keycard
Level 5: Light Armor, Traps
Level 10: Hacking
Level 15: Medium Armor
Level 20: Deploy Turret
Level 25: Sub-Machine Guns
Level 30: Firewall
Level 35: Demolition Expert

Spec Ops
Starts with: Pistols, Submachine Guns, Surveillance PDA
Level 5: Sensor Jammer
Level 10: Light Armor
Level 15: Assault Rifles
Level 20: Medium Armor
Level 25: Knife Attack
Level 30: Adv. Heat Sensor
Level 35: Critical Hit