Need help. Starting new job

My Porter Cable drill and impact set was stolen out of my truck late last year. I used them a couple times a week and they were fine for my uses. I'm now switching crews and will be working with Industrial Solar Panel installations and will be using the impact much much more, so I definitely want something up to the task. Most of the guys use Dewalt and seem happy and having the same batteries as everyone else would be nice, but I want to hear opinions. While using the tools, the main use on these jobs will be driving lag bolts.

Are the Kobalts even worth looking at simply for their inexpensive batteries? Is Dewalt going to be my best option? Or would you recommend a different brand? Also should I look into getting an impact wrench as well?

Tl;Dr - Driving lots of lag bolts, looking for best drill/impact combo. Most of the crew uses DeWalt. Is getting an impact wrench in addition a good idea?