Many DIY lighting systems assume that you want to fabricate a lamp unit and the electronics. You can buy dynamo-style lamps (with mounting bracket) pretty cheaply. You can power these from a dynamo/generator or a battery. I use a rechargeable battery stuffed into a waterbottle, and bought a recharger from an electronics store.
Modern LED battery headlamps seem pretty effective.

For panniers, look for a modern quick-release, locking mounting system not the old fashioned hook and elastic.
Get tough material. A flap is more useful than a zip closure is you need to overload the bag.
You need good stiffening material on the back and base.
Some have lots of compartments, but I prefer on main and one side pocket.
You can use a single pannier quite safely.