Sorry, was hoping some of the guys more knowledgeable on Hi-Fi would respond (I'm more into Home Cinema)! However, I haven't heard it, but you could go for something like the
Marantz PM6002 amp (won the award this year in WHF for best amp under £300). Team that up with some decent speakers and stands and this would sound pretty good - I can't recommend any as, not having heard the amp, I don't know what would go - WHF recommends the
Dali Lektor 1 with this amp though.
Your other option is to for some active speakers which include the amplification within the speaker so you don't need the separate amp. Something like the
Audioengine A5s. You could add a separate DAC to this like the
Cambridge Audio DACMagic which would present a pretty formidable sound I would imagine.
Please note, I'm guessing here only - I haven't actually heard any of these systems so you should definitely audition first if you can!