Monitors for Pass Labs 60 INT

Can i suggest the harbeth M30.1 ?is efficient enough to Give juice from pass.

I think you need to move up,the Pass Labs line and buy more watts per channel. All of your favorite speakers, including the Kef's are not going to sound their best with less than 150 wpc at 8 ohm and 275-300wpc at 4 ohm. Anything less than 90 db efficiency is a tough load and probably has an impedance drop below 4 ohm if it is a two way speaker.

You may want to consider Focal's as well .  I drive a pair of 1008Be's with XA100.5 mono blocs with very good results. They are efficient enough where the INT-60 should do fine for most music at reasonable volumes. You may also want to consider the Focal Diablo.

Big mistake to not try Revel M106's. Just great speaker builders with huge budget for R&D. Just my opinion as a two pair Revel owner. 

What sound reproduction/speaker characteristics are most important to you?