It seems to me that there are three very good possibilities, each of which has its own merits.
Warpig
Miracle Man
Holydiver
Each will do a fantastic job so it depends on what you want to prioritize.
Warpig
I'd go with the alnico version as it will be a little more versatile and have slightly sweeter leads. With all that bass your little RR3 will sound monster huge! The downside is that versatility is a relative term and although it may be a touch more versatile than the ceramic version, versatility won't be its strongest suit. If you're the only guitarist in the band and you're playing a pickup with a lot of bass in it, you may get a bit too crowded down at the bottom end so you'll end up competing with the bass. That means your guitar won't stand out quite so much in the mix. Worth considering. For this pickup, think Tony Iommi and Black Sabbath.
Miracle Man
This is another pickup with a huge bottom end but not as overpowering as the Warpig. The bass is supported by lots of lower mids so although there's a lot of bass going on here, it's not so heavily concentrated right at the bottom end. The Miracle Man also has a fair chunk of highs that really cut through and pinch harmonics can jump out all over the fretboard. This is the tightest of the three and the most aggressive. There's a lot to like here in your guitar if you want a heavy bottom and great leads but you do sacrifice the cleans a bit because of the ceramic magnet. Zakk Wylde is the obvious connection here but that always gave me the idea of an EMG 81 and such a description doesn't tell the whole story. Yes, it's tight and aggressive and has the pinched harmonics but the tone is also surprisingly thick, smooth and organic. Think of the tone you might associate with Metal from about 1985 to 1992 (approximately).
Holydiver
In many ways this is a very good compromise and is easily the most versatile of the three. It doesn't have the huge bottom end of the Warpig and Miracle Man but it does have the sweetest lead tone of any of the hot Bare Knuckle bridge pickups. It's certainly not lacking in bottom end, it's just that it's not as obvious as the other two. It's smooth, thick, warm and organic with plenty mids so it should cut through the mix nicely in your band. It's not as aggressive as the Miracle Man or as tight but it is still quite a tight pickup with a decent amount of aggression so good for Metal music. Primarily think of Metal music from about 1980 - 1988. Dio is the obvious musical reference for this tone but I'd also think of Doug Aldrich and Jake E. Lee. With a decent overdrive pedal it will take you into more modern Metal territory and back down on the gain and it will do good Classic Rock tones. I use mine for everything from Doobie Brothers to Metallica and Children of Bodom, though neither of those extremes are its natural home.
So there you are; if your main priority is a huge bottom end, get the Warpig, if your priority is tight and aggressive chugging with screaming leads, get the Miracle Man and if you mainly want versatility that is aggressive, tight, warm, smooth and thick, get the Holydiver. TBH, if you're the only guitarist in the band, I'd be tempted to focus more on the Miracle Man and Holydiver, leaving the bass to the bass player.
