• Field Supplies (You can run contracts for HD ammo and buy it with cash. Points are more valuable)
  
• Pay Grade (Have a look at point 8.)
  
• Energy Boost (You can boost max energy in equipment auguments and better skill is Energy Regen)
  
• Health Regen (Unprofitable. Your main clearing weapon should have biosynthesis so you just throw away points at that skill)
  
• Recovery Time (YOU MUST SURVIVE!)
  
• Grenade Damage (You won't even see significant diferrence, even with 375% additional grenade damage)

Originally posted by SAS Zombie Assault Wiki:

Reload speed - the number stacks multiplicative with base reload speed first, then other multiplier augments or other reload speed effects. For example a gun with 2 seconds with reload speed 50% from skill + 25% reload speed from nimble augment + 50% from Adrenaline will results in calculation of 2 x (1-0.5) x (1-0.25) x (1-0.5) = 0.375 sec reload time instead of instant reload. Titan IDS arm and nimble augment stacks additively as one multiplier.

• Most important is adrenaline skill and speed. Invest that one point into Stim Shot for "a backup plan" when you're in troubles.

• As fast as possible have 1 adrenaline, 1 killing spree, 1 crit and 4 reload.

• It's really good choice, you get lots of HP and assault special skills.
  
• I used a hotspot for low lvl's, flamethrower for mid lvl's and shockfield for high lvl. Homever you should use what you like (but you need to know how to compare weapons and don't use junk).
  
• First one point into adrenaline, killing spree, 4 reload.
  
• Your armor can be all dragonfly or mixed dragonfly/medusa with rubicon vest.

• Try to have good armor and biosynthesis on clearing weapon (Btw everybody should have this)

• Try to have fast shooting, fast reload weapon.

• Key for that build is high resistance and health regen with armor. Trust me, if you do it right you can face-rush most of bosses.

• You'll have a medkits, good armor, good speed, faster reload and a bio bomb. What you need more?
  
• I recommend to have some energy regen auguments on armor and some more speed.

• Critical medic is interesing build. In high lvl's you should use stripper or maybe hornet/hotspot.
  
• Place one point into critical shot, then one bio bomb, few reload and then go as you like.

• Be aware, this build is just support. You'll likely die most of times but your team should be playing like few lvl's better. I highly recommend that build only when you have some friends to play with, no random people. It's really helpful build for organised team but also you'll need some help to survive.
  
• Armor can be all for speed with energy regeneration auguments or speed/resistance with energy regeneration. You need at least 5.5 energy/s (I recommend 7.5 energy/s) if you can't have it try less points on something (final decision is yours) and put 5 into energy regen skill.
  
• First one point into bio bomb, then one final farewell, 2 reload and then what you want till zombie antidote (you want to max it out)

• This build is to emitate the heavy build on medic. You can easily boost your biosynthesis on gun with medkits.
  
• For sure, you need to have energy regen. Obtain this by auguments on armor. It's important to spam bio bombs and still have some spare energy for medkits.
  
• First place your point to unlock bio bomb, then some to reload/BAE and then as you want - amount matters.

• Try to be like me (but to be honest, don't, it require so much time and grinding. If you still want - see my guide about broken mechanics):