Try Proac. I am using a EL34 powered Quicksilver V4 amp with Proac Response 2.5. You might try the Response 1.5 or Studio 140 (both used would fit your price range)as they are more sensitive and would work better with your 40 wpc amp.
Speakers for EL34 amp: $1,500 - $2,000
Looking for floorstanding or stand mount speakers that work well with EL-34 amp (approx. 40 watts). Price range: $1,500 - $2,000 new or used. Transparency, Soundstaging and Tonality are most important. Musical taste is varied, with a heavy dose of female vocalist, Jazz and tasteful pop. Room is 14' x 12'. Thanks for your suggestions.