I’ve played both the HD and Juggernaut, so I’ll weigh in. The HD is definitely more vintage voiced and can be pretty aggressive, it also works great in guitars with Floyds and has a great lead tone. It could be a very good option, only thing is I don’t have experience with a HD tuned that low (I’ve only messed with it in standard tuning). The Juggernaut is more modern, but I was very surprised by its tone. It is very versatile and can do everything from clean to ultra high gain. It handled drop C really well. It’s tighter than the HD, but that isn’t to say the HD isn’t tight because it is. I don’t know if the Juggernaut would be the right call here because it is lower output than the Nailbomb and not as aggressive as even the HD. It is a really good pickup though, and I think the advent label turns people off, but it does so much more than that.
With a Strat type guitar with a Floyd, it is going to have less inherent low end compared to an Explorer. The HD fattens up a Strat nicely, but what about a Warpig? I haven’t tried them in a super Strat, but I’m considering putting one in a really bright super Strat that I have. I know you have experience with Warpigs, and they should work for the style you play. That huge bottom end might be the ticket for getting a super Strat to sound like an Explorer with Nailbombs (though I have not yet tried a Nailbomb and don’t own an Explorer, so this is just a guess).
For the singlecoils, what are you looking to get tonally from them?