I run my Manis using a pair of B&K M200 Sonatas. I've owned many B&K amps and the M200's are by far the best IMHO. I've also used many other amps with the Mani's (CJ, Parasound, Bedini, Ayre) and the M200's are by favorite with them. The Manis are reputed to be fatiguing depending on what they're paired with, but this isn't at all an issue with the M200's.
It's not hard to find M200's for ~$500-600 depending on the condition, and at twice that price they're hard to beat. (I noticed there's also a pair listed on ebay right now - I have no relation to the seller).