Sounds like you would enjoy modified B+M lights like Laempie.de offers.
He has several models with switchable flood lights and even ones that use a battery pack to increase the light even more.

• https://www.laempie.de/cyo A modified Cyo Premium with switchable flood light 80/110 Lux
• https://www.laempie.de/mk4 his own design with long-throw, floodlight or even battery-added light.
• https://www.laempie.de/luxos A Luxos with extra LEDs that can go to 130 lux in flood light setting to even 200 lux with an external battery

Other than that I would recommend using SON's coaxial cables and connectors in all the places it makes sense as it will probably just pop open if it snags in a crash.
It also allows for the use of things like:

• junction boxes
• quick release plugs on your dynamo
• Coax plugs
• coax adapter for another quick release hub option