I am planning my hardware choices for building what will be either a six-string bass or an 8-string guitar (don't know quite yet). Doing my homework, I've found six-string bass pickups from EMG, Aero, Villex, Delano, Status and Nordstrand.

Are there any others out there that you guys especially like?

My Warwick 6 has Seymour Duncan active BassLines that I really like.

When my bass will be ready, I'll tell you how I like LeFay Rough Crystals; they are just sitting on my cupboard now. I've heard good things about them.
Anyway, just wanted to say there are many more options than just those. There's also Bartolini. and some more...

I've got Delano Quad coils in my Bee bass and I'm really happy with them. Definitely hi-fi and crystal clear.