I've owned a few PRS Custom 24 guitars, albeit only the SE versions and I've tried a few pickup variations. My favourite all-rounder was probably the Crawler. Its natural home is Blues Rock but it will cover anything up to early 80s Metal without difficulty. It's often described as a 'dark' pickup but that's a little misleading. It does certainly have a strong bottom end but the misleading impression of darkness is because the mids in this pickup are focused more on the low mids, making the pickup sound huge. You get some really fat and sweet leads from a Crawler. The tone is very rich and has an incredible growl to it. Of all the pickups I'd suggest for you, this one is the softest in the bass under gain but it's not mushy by any means at all because by the time it starts to give up, you're into fairly serious levels of gain and against that, it has the best overall tone, the best leads, the best cleans and the best splits. Honestly, this is an astonishing pickup in a PRS.
Another fantastic bridge option for a PRS Custom 24 would be an Abraxas. It uses the same wire as the Crawler but uses an AIV magnet instead of AV. This would normally suggest a softer bass response but the lighter wind means it isn't as dark overall and that little bit of extra brightness helps to keep things very articulate. Don't be fooled by the name, the Abraxas will do your progressive Rock and Metal all day long and offer tremendous versatility. Superb tone, great cleans and sweet leads make it a very attractive proposition. This pickup is certainly related to the Crawler, it's just dialled back a bit so not as dark and growly.
The next option would be the obvious one, which is the Holydiver. This one is clearly aimed at that 80s Metal tone but because it uses 44AWG wire instead of 43AWG, it actually ends up sounding a bit more modern than it should so if anything, the Abraxas has a more authentically 80s Metal tone. The plus side is that has stong mids across the board, great leads and remarkably good tone for a contemporary pickup. It's the tightest of these three. Some people can say the prominent mids make it sound a bit honky in a PRS but I always found it absolutely fine.
For the neck pickup, for me at least, it's a straight choice between a Holydiver and an Emerald. Surprisingly, the Emerald is the hotter and more modern sounding of the two. Both are awesome but based on your description, I'd say you want an Emerald as it ticks all of your boxes. Essentially, what you described IS an Emerald.
There are some good reviews of all of these in the Review sticky and if you need any more information, just let me know.
