Q: Rear flood lights or a roof light bar: which should come first?

They solve different problems, so it depends where your truck goes at night. A roof-mounted bar such as the 50 inch double row unit in the INVINCIBLE lineup throws light forward and far for moving on trails. Rear floods work close and wide behind the truck for hitching, recovery, and camp. Overlanders usually end up with both; if your pain point is backing up and working after dark, start here. The UP FULL INVINCIBLE Build shows the full lighting menu in one place.