Part of it is simply personal preference, part is personal experience and part is based on what I've learned from other posts on this board. First off is your guitar. My experience with the Nailbomb was that there were a lot of high mids in it and it was very aggressive sounding and incredibly tight. I felt it needed a darker guitar and while yours would be better suited to it than mine, I still feel that it's a pickup that would sit best in mahogany. I also found it to have a very distinctly 90's Metal feel about it and though it could do other things like Classic Rock, it always retained that 90's Metal feel about it. The Nailbomb's a tricky one though because there are plenty people on here who have very different experiences of the Nailbomb. I was initially tempted to conclude it was just me but equally, there are also plenty people who have had a very similar experience so maybe it's just very picky about the guitar it goes into. It may well work for you but based on my experience (what else can I go on?) I'd consider other options unless of course you're looking for something that's super tight, very aggressive and has lots of high mids. The Holydiver on the other hand may well be described as 'thick' but it certainly isn't bassy and seems to work in almost any guitar. The inherent smoothness of the pickup helps to make it quite versatile in my opinion because it allows it to drop into Classic Rock with ease, nails 80's Metal and kick an overdrive on and it will take you straight into modern Metal. It's not the best option for 90's Grunge but it will make a decent fist of most things and there's no pickup that will do everything. I don't think it's the most versatile pickup in the BKP and I don't even think it's the most versatile pickup in the contemporary range but it is the best overall fit for what you're after in my opinion.
As for the neck pickup, it's again down to a lot of personal experience. I used to favour the Cold Sweat neck and I still think it's fantastic but one day I was talking to Tim about using a Holydiver in the bridge of my PRS and I was thinking of a Cold Sweat or maybe a VHII for the neck. He said he loved the idea of using the Holydiver and while the Cold Sweat and VHII would work well, he strongly suggested I tried the Emerald as the Holydiver/Emerald combo was one of his favourites. Oh mama!! What a sensational pickup it turned out to be. BKP have lots of good pickups to choose from and many of them are very closely connected. The Mule, Abraxas and Crawler necks are all very similar for instance, as are the Holydiver, Rebel Yell and Cold Sweat necks. The Emerald neck, however, is absolutely unique. The AIV magnet gives it a more vintage feel than anything you get in the contemporary range so in that respect it's like the Mule etc. but unlike them, it uses 43AWG wire instead of 42AWG and that makes a huge difference. That brings in a more modern feel as every other pickup using 43AWG in the neck is in the contemporary range so while it has all of the sweetness you get from an AIV magnet, it has the cut you usually expect from an AV pickup in the contemporary section. It's also a hot pickup, being wound hotter than many of the neck pickups in the contemporary range. Cleans are sublime, articulation is superb and and leads are incredible, being able to take masses of gain. With an Emerald neck I can play anything from Blues to modern Metal as absolutely nothing phases it. There are other neck pickups I like but the Emerald is head and shoulders above anything else I've ever tried.
I'm not saying this is your only option by any means. You might like the Rebel Yell as it's a slightly toned down Nailbomb, you might like the Cold Sweats if you want something brighter and tighter. You might also consider the Black Dog as it shares some of the characteristics of the Holydiver but in a more Classic Rock rather than 80's Metal format, but the Holydiver is what I'd look at if I were you as it simply does an awful lot really well. As for the neck, I just can't praise the Emerald highly enough. If Tim suddenly said he wanted to do me a signature set of my own, for the bridge I'd ask him to work on something that was a cross between a Holydiver and Crawler with maybe a hint of Miracle Man and Cold Sweat thrown in for good measure but for the neck, I'd just ask him to put my name on a copy of a stock Emerald. I just can't think of a thing I'd change about it.
