S-10 Headlight Guide?

I've been using Google to search this forum and can't find a definitive answer on this. What's the situation with S-10 headlights between the different model years? I have a '97 S-10 SS and was just at O'Reillys and got headlights for it and they're the wrong size? They're fixed headlamps where you can't change the bulb, and the ones on the truck are smaller than what O'Reillys gave me. A google search on the old ones says they're H4666. Are these smaller lamps and were used on the older S-10 and a previous owner had converted them? The front of the truck looks aftermarket and has a bumper with holes for foglamps.

Also, for the older fixed lamps, is there a way to upgrade to the socket-style (composite?) lamps so I can get much more powerful headlights? I see LED options on Amazon but I want a more stock look. I've researched and there's wiring harness adapters but how do I get a lamp assembly that's this size and I can change the bulb?