Given your source preferences, one unit that impresses me sonically as well as from a flexibility standpoint is the Naim Uniti. It's an all-in-one player that performs the functions of an integrated amplifier, CD player, DAB/FM tuner, internet radio, iPod dock, digital-to-analogue converter, music file player and network stream player. If you can audition it, you may find that it seriously upgrades your source and amplification quality all at once as well as providing a comprehensive audio hub, and does it all in one tidy box that sells for less than $4000.
Of course, if you're set on the 803d speakers, then you'd want to hear the combination first. The power output from the Naim is on the lower end of B&W's recommended range, but reviewers of the Naim have commented favorably on its ability to drive even notoriously difficult speakers, such as Quad ESL's (which, at least on paper, should be a more difficult task than the 803d's due to their lower efficiency and more wildly fluctuating impedance curve).
Of course, if you're set on the 803d speakers, then you'd want to hear the combination first. The power output from the Naim is on the lower end of B&W's recommended range, but reviewers of the Naim have commented favorably on its ability to drive even notoriously difficult speakers, such as Quad ESL's (which, at least on paper, should be a more difficult task than the 803d's due to their lower efficiency and more wildly fluctuating impedance curve).