My bad, forgot it’s not disc.
Re: lights, my only experience is exposures Revo - which is bright as balls, and do sometimes come up cheap second hand, as people generally forget exposure make a dynamo light.
Re: charging, I bought a VeloCharger, it’s £60 odd from SPA, unfortunately I can’t say much more than the fact it works and seems to be built relatively well, with a nice waterproof gland where the cable breaks - for removal. I haven’t really put it trough the ringer though so can’t comment on reliability, but I believe it comes with a pretty comprehensive warranty. They claim they’ve had next to no failures (possibly none?), I did email the guy who designed it quite a bit before I pulled the trigger, I can dig them out and see what he said if you’re interested.
In terms of wiring you either wire them in parallel (not series), which is fine - but means you won’t get full power from both the light and charger if running both together. Or you do what I did and wire them to a switch, so you can select light, charger or neither.
Another option is the K-light that’s second hand on STW classifieds at the moment (although over budget), I very nearly bought it myself and still might if no one else does. It’s basically the Bentley of Dynamo lights. The Aussie chap who designs them did a podcast interview (I think on the bikepack Canada podcast) and it’s immediately apparent why they’re ubiquitous on MTB ultra races and what-not.