With regard to your source choice, I have owned the Esoteric D-07, D-05 and P-05 and will have the K-03 in a week. In my opinion, the K-03 is the best bang for your $. It has asynchronous USB input, and a built in volume/digital pre that's quite good and (as I understand it) is closer to the K-01 than the K-05 in sonic goodness. It also has the newer (and supposedly better) DAC chips than the D-03. Benefits are reported as better high end detail, more air, etc. Cost is probably about a wash. Another good choice would be the Playback Designs MPS-5 IMO.
As far as speakers, I've heard the Alexias in RMAF last year in 2 rooms and I was not overly impressed. However, when I heard them in Dallas, not only did they sound significantly better, but they had minimal resemblance to what I heard at RMAF (Note: Steve was almost drooling when we heard them). They were very good. From my experience, clearly, they are very sensitive to connected electronics.
In your budget, I would also suggest checking out the Vandersteen 7 (One of the most clear, spacious detailed yet pleasant tweeters I have ever heard, fantastic bass, highly adjustable), Evolution Acoustics MMtwo and Rockports (I think Steve already suggested them). All are rated as awesome speakers. I love TADs but they seem to be either below (Evolution One) or above (TAD reference) your $. Of course, I love my Ushers which I think rank higher than their price point.
Good luck in your search, with your budget, great dilemma to be in...