I was thinking a Headroom Ultra Micro DAC with Micro Amp might fit your price ($1,100) and other requirements. It should sound about the same as the HR Desktop amp (with Home amp module and MAX DAC), but will be $350 cheaper since you wont need the upgraded Desktop Power Supply. And you could upgrade the amp later while the Ultra DAC is already close to the DAC1 and Apogee mini-DAC level.
Right now my Micro DAC and Micro Amp via USB are sounding almost the same as a PICO, but it warms up nicely with the crossfeed on, and the optical from my laptop adds another small performance boost over the Pico. So, the Ultra Micro DAC should be even better.
Another option is the Apogee mini-DAC with firewire option (if your computer doesn't have optical or coax out), and it does a great job driving single ended or balanced headphones without an amp. It also responds very nicely to a better regulated power supply like my $89 Radio Shack laptop PSU, and even better to a more costly Sigma 11 PSU - so you can start off in budget and upgrade later.
