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I'm looking to build a multichannel (6 or 8 channel) DAC with differential balanced outputs...

btw: when playing movies using a HTPC and a USB - DAC - is it easy to keep the video and audio in synch or is that something that needs manual delay correction every time?
If its a pain to keep the audio in-synch with the video on a HTPC - then I'm probably better-off going for an A/V processor with HDMI - such as Sherbourn PT-7030 or Onkyo PR-SC5509.

As for the DAC - I've already looked at products from Lynx, RME, Focusrite, Digigram, Motu, M-Audio, Roland, Behringer, Wadia, Matrix, Mytek, Resonessence etc and the following options seem to come closest to exactly what I want..

The exasound e28 is perfect and exactly what I want - but well beyond my price range... 

The Twistedpear - Buffalo is something that will need work putting it together and could run more than $600 total

The AKM doesn't look bad - but the performance figures aren't as good as the e28 or Buffalo.

Due to lack of any other viable options... I think I may have to embark on a DIY for the Ultimate multi-channel DAC that would rival the best 2 channel DACs from Antelope and other premium stereo DACs.

Ideally - I'd like to have someone (or a few people) experienced join me in this venture and build this DAC and if sufficient interest is there possibly market and may be even sell this under a direct-internet sales model (like exasound)....

Following are the broad requirement specs:

1. Asynchronous USB input with buffer (no need for SPDIF etc)
2. Automatic PCM / DSD Switching (native DSD support)
3. Remote control for power, volume and mode selection
4. Full balanced opAmp and line stage circuitry to get 8 channel line level true balanced outputs to gold-plated 3 pin XLR jacks
5. Power Cleaning Stages - Noise, Crosstalk and Jitter Reduction
6. USB ground isolated galvanically from the DAC and the analogue circuits
7. Digital subsystem powered independently and isolated galvanically from the rest of the board.
8. Like the e28 - does it make sense to have separate Quartz oscillators for (44.1, 88.2, 176.4, and 352.8 kHz) and (48, 96,192 and 384kHz) and another Quartz oscillator as reference master clock with 0.13ps precision for D to A conversion?
9. Need not have internal power transformer - may be we can feed DC power using external laptop-adapter style transformers...
10. It would be nice if its a modular 2ch DAC design with a single USB digital input but with the ability to upgrade by adding expansion 2ch DACs - so as to make 4ch, 6ch, 8ch,10ch or 12ch balanced analog outputs.

Some other considerations:
DAC chip: ESS Technology ES9018 Sabre Reference 32bit (even though its a 8 channel chip - I'd like to use it 4 of these as a stereo DAC for better SNR and Dynamics)
other options is a Texas Instruments - Burr Brown - PCM1794A or DSD1794A or PCM1690?
Any other DAC ships to consider that are 24bit/192kHz or better?
What would I need to complete the above project?

Other components
the best quality components (Nichicon etc) for the power and line stages
gold plated XLR or miniXLR outputs.

How much would such a DAC cost?
Is there anyone out there who can design and build the ultimate multichannel DAC?
Can this be done for well below the price range of the exasound e28 and closer to around what the Buffalo DAC would cost?