Literally any bookshelf speaker will do, except perhaps the LS50 which is a pain to drive. Finding a bookshelf speaker with 95 db is an impossible task. 86db is good enough! Don't be swayed by Klipsch speakers which overrate their efficiency numbers.
With $2k you have too many options I'm afraid.
I'm using Closer Acoustics OGY which were purposefully built for tube amplifiers and are rated at 91db 8 ohm 15W max. Good luck beating that efficiency number on a bookshelf speaker! This one has a single EMS LB5 driver with a transmission line cabinet. Yeah they sound incredible with jazz, folk and pretty much anything. Probably not the best for metal and extremely busy electronic tracks but they hold their own. The limitations of fullrange drivers are overstated.