About the best buy in your price range are the new Elac F5 towers. Read the reviews on the B5. B6 and F5 Elac speakers. The only down side is that they are not very efficient at 85db sensitivity.

ELAC Debut F5 Tower Speakers (Pr) at Music Direct

speakers ? Welcome to ELAC Americas

Music direct also has a pair of Wharfedale towers for sale. But they are rated at 86dB.

If you go with low power tube amps then you will need a speaker rated above 90dB. Give Klipsch a look. The one below is rated at 96dB and will play ear bleeding loud at 10wpc.

Klipsch Reference Premiere RP-250F (Cherry) Floor-standing speaker at Crutchfield.com