General advice here;
Power ‘required’ can depend on who you ride with. If other people have 2000 lumens, you might struggle to ride in front of them with say, a 400 lumen set, as you’ll be in your own shadow. You can get away with pretty low powered lights if you are on your own, or if everyone rides with similar powered lights.
If you’re riding twisty stuff, mounting the light on your helmet helps lots. Riding an area with lots of humpy bumps with only a headlight can be a pain too, as it’s hard to see the bumps. If you do have a light on your helmet, careful where you look when you have a stop. Your riding mates won’t appreciate being blinded.
Do get a fast charger if there is an option. Nothing worse than missing out on a ride by forgetting to charge your lights when they take 8 hours to charge.
Personally, I run a 2nd hand Niterider Pro LED 700 on the head and add a Light and Motion Seca 400 as a bar light as required. Tested a set of Ay-Up V4s a couple of winters ago – awesome, but got a great deal on the L&M Seca.