Personally I have some experience with one of those early '90s Les Paul Studios, having installed an Emerald set in one.
The first thing I'd say is to avoid the brighter pickups in the range like the Emerald, Riff Raff, Stormy Monday, and Rebel Yell. They sound thin in those guitars. You want something with a nice fat bottom end. I might be inclined to avoid the Black Hawk, Aftermath, and Painkiller too.
Humbuckers that I would consider for that model are Abraxas, Crawler, Holy Diver, Cold Sweat, Nailbomb, Juggernaut, Miracle Man, and Warpig. For what you want to do - I had a listen your recording and really liked it, I am probably the guy on this forum working in the style closest to yours - I would probably go for an alnico Nailbomb. I have one in my Explorer and I like it for sludgey stuff and I've had pretty good results with trem picking too. The matching neck is also nice, quite bright. I would say that the bridge pickup is really a rhythm pickup, not amazing for leads. My other guitar for the band is an SG with an alnico Warpig set. I would also recommend that pickup to you, but it is lacking the treble detail of the A-Bomb, which I think would suit you best. I'd recommend either going for the set or, if you want a different neck pickup suggestion maybe the Holy Diver neck