I do a lot of solos and need something that will give me tons of sustain. I like higher gain however I want to be able to have that classic rock vibe but with the ability to crank it up and really make the solos scream and sing. I want the pickup to help with flow of notes, legato and two hand tapping together with really good pinched harmonics.
best bridge lead pup I ever experienced was definitely the Holy Diver
the Holy Diver is perfect for early both early and modern Van Halen and also for Jake E. Lee and Doug Aldrich stuff
not really a classic 70's tone, but it works well for pretty much everything, in my opinion
usually Tim recommends the Nailbomb for versatility, but it's a much hotter and more aggressive pickup
the bridge Cold Sweat is way more stiff sounding, brighter and more focused on both rhythms and leads, specially through a JCM 800
I don't think that's what you're looking for at all
the Black Dog might be a great option, though
I wouldn't go with the Mule for the neck if your priority is the lead tones
it cleans up like no other pickup I've tried, but it has no near the sustain of the neck Cold Sweat on leads, for example, as it doesn't drive the amp as hard (although the neck Cold Sweat is also medium/low output, and quite smooth as well)