Have multiple schmidt hubs and various lights (supernova e3, edelux x 2)
if i had to pick one setup: the sondelux hub and supernova symmetrical (round) beam for truly dark riding outside of cities, Edelux for city riding where there is some ambient background light.
To save money, id look at the cheaper hubs, or preferably find a used son28 hub when someone upgrades to sondelux.
The most important part of the investment is the lights, spend on those first.