headlight recommendation for my Duster

Crackedback is right about relays and good wiring, and his kits are A1. I consider his warning not quite strong enough about those cheap Chinese harnesses all over the place on the internet. Best avoid them altogether; they have a nasty way of failing while you're in the middle of using the headlamps to stay alive; maybe a spare relay in the glovebox will save you, and maybe it won't. Truly, if it's a choice between gambling with one of those and living with the limitations of the stock wiring, the second option is the smarter and safer one. Fortunately those aren't your only two choices.

There are no longer any worthy sealed beams on the market; they are all garbage. If you gotta-gotta-gotta have original-type headlamps, pick up a pair of old-stock Philips, GE, or Westinghouse halogen sealed beams; the older the better.

If you want good headlamps, pick wisely; there is a mountain of garbage on the market, and it's all hyped as an "upgrade". The Hella items are passable if you get good ones—not great, but relatively affordable. "If you get good ones" needs more attention than usual right now, because Hella had a major freakin' "oops" not long ago in the 3rd-rank production line they moved these lamps' manufacture to awhile back, and the glass lenses on them were so fragile that a significant proportion of them were not surviving the trip across the ocean, and a similar proportion of the survivors were breaking spontaneously on warehouse shelves or in transit to stocking dealers or end-user customers. Hella recalled all of them some months back, then set about refilling the pipeline (not a high priority; 7-inch lamps don't sell in nearly the volume they did decades ago), but there are still fragile ones in the wild.

If you decide to go to Hella anyway, these, specifically, are the ones you want, not the "E-code" (ECE); Hella's ECE 7" round headlamps are poorly focused—aim the lows where they should be and the highs are up in the trees; pull the highs down where they should be (straight ahead) and the low beams end much too close to your front bumper. There are (much) better brands of H4 headlamp, if what you want is a lamp with a facetted glass lens that looks like it belongs on a classic car.

LED headlamps: there are good ones, and they don't necessarily have to look like they came off a '15 Honda or a spaceship. But there's also a(nother) mountain of garbage, including the "Holley" (brand only) "Retrobright", which is beyond bad and into unsafe territory. You don't even have to spend a giant pile of cash; read this (and post #10 in that same thread).

Whatever headlamps you get, they gotta-gotta-gotta be aimed correctly.