I got Fishman Neo-D humbuckers for my guitar and bouzouki recently, and I'm very pleased with the results so far. It's essentially a passive version of the Rare Earth (I prefer to use passive pickups with an external preamp for various reasons), and I'm pleased with the sound - plenty of zing in the top end, and not the clunky middly tones some magnetic pickups give you.

They cost around £70 each. I'd recommend having them wired to an endpin jack rather than the trailing lead they come with.