Perks:
Commando
The SWAT:
All weapon damage is slightly improved, although the dualies and shotgun seem to be the weapons that perfectly fit you. Those also get an ammo upgrade and in the case of dualies an accuracy upgrade. Moreso, your flashlight dies at 60% slower, due to your efficent knowledge of how to use it without wasting battery life.
The Special Forces:
You are the master of close quarters combat. Melee speed, damage and running speed when melee out increases HUGE. Also, due to your close-combat nature, and thus your lessons in evading enemies, Clots can't grip you. You also receive less damage.
The Paratroopers:
Because of your comfort of use with the SA80a2 Carbine you are extremely effective with it. More damage, less recoil and a bit more accurate. Furthermore, due to your keen observation skills, Stalkers are even visible when cloaked to your highy trained eye.
Medic
The Healer:
Allows better TEAMMATE healing. The syringe is heavily improved for teammate healing, also gives them 125 hp instead of 100.
The Lone Wolve:
Allows for better SELF healing. The reload time for self healing is greatly decreased, also you get major resistance against bloat bile and somewhat against the siren scream
The Field-Medic:
This one has only slight improved overall heal-capacity(self and team), but gets a nice speed bonus, so he can get to teammates who need healing quick.
Sharpshooter
The Sniper:
Headshot damage increases exponentially, also, most weapons are able to sever a head of ANY specimen (except the fleshpund, which takes 2) in ONE shot.
The Camper:
Man you like nothing more then sitting in the back with a big stash of ammo, covering your buddies back whilst staying out of the fray. A clot there a scrake here and everybodies happy. 150% ammo increase for the crossbow, 35% for the Winchester. accuracy is somewhat increased.
The Eagle Eye:
You take aim. You breathe. You shoot. Nothing beats your accuracy. Most weapons get dead on accurate, except for ones that would be overpowered. Also reduced recoil.
Support
The Heavyweight:
You are one tough *** mofo. Due to this you can carry more grenades and ammo. Furthermore recoil is reduced quite a bit and the shotgun and handcannon are somewhat more powerful.
The Pyromaniac:
You love fire. You love heat. The flamethrower is your life and the welder your love.
Welding speed increased by 35% allowing for quick sealing of rooms. The flamethrower has more power due to your know-how on how to make things burn better and faster.
The Grunt:
You know the drill of the biggest of weapons. Hunting Shotgun is quicker to reload and a tad stronger, also more ammo for it. LAW unlocked, and more ammo capacity for it.
Feel free to edit and rework any of those perks as you see fit. I just think some of these are neat basic sets of perks. Also, couldn't really think of any good base perks, so Ill leave that up to you lot.
Mind, the berserker perk totally merged into the Green Beret sub perk.
For the berserker perk you could have a swordmaster(damage dealing) tank(damage taking) and street fighter (inbetween balance of the two).