All Maple with Ebony? Now that is bright like hell, the Invaders should already counterbalance that wood combo pretty well, what tuning are you in? Remember that no Contemporary BKP will be muddy like the Invader, I have a pair of SH-8s myself in my Mahogany, Maple Neck, Rosewood Fretboard Jackson and surprisingly they are tighter in it than they were in my Basswood Body, All Maple Neck Ibanez. I know your problem too well, as the Invaders have crushing mids and a boomy low end but in deed lack tightness. My Holydiver is tighter and it's an Alnico 5 pickup. Now if you REALLY want the piercing highs Black Metal Sound, you could go with a bright Pickup like the Rebell Yell, but be aware that for normal ears and standards it will be overbearingly piercing in the mids and highs. I'd recommend you to look at something that counterbalances it, maybe the Miracle Man could give you what you need.
To be honest I can only guess everything I've written by now, so you might just wait that someone else pops in and states his opinion. Or you could email BKP directly.
