Personally I preferred to use shield barrier. The problem with using the tech heals is that if you fail and have to restart the checkpoint, they are GONE, meaning you have to replay the level in its entirity (and also meaning you might not have 3 of them next time you get to the end of the level).
I placed one shield down right behind Jazz just before the turrets came out, another just after I destroyed the two turrets, and a 3rd when the largest group of enemies came after the turrets were down. The enemies rarely rush into the barriers, and they will protect Jazz enough to keep him alive.
Also, the shield barriers don't disappear from your inventory if you fail and restart the checkpoint.
I also used the Path Blaster, not the techvolt, because if you headshot enemies it's usually a 1-2 hit kill meaning I was killing faster than I did with the techvolt. This is personal preference though.
Lastly, make sure you set the difficulty to Easy (goes without saying) to make this as easy as possible.