USB E1 interface required

We're looking for someone to design and prototype a USB to E1/T1 interface. Ideally, we'd like to be able to offer 1-8 E1/T1 ports from essentially the same design, and have enough DSP on it to allow on-card echo cancelling. The TMS320VC5509 DSP has enough RAM and horsepower for 2-4 E1s, so this might provide a starting point - it's also got a USB interface, from which it can boot. Something like a PM4354 might do most of the rest of the work. We're looking for: - schematics designed - layout done - prototype(s) built - software to "proof of concept" level - e.g. E1 essentially passed through DSP into Asterisk. Special bonus points for coming up with a design which'll fit on a PCI-E mini card (which, of course, has USB 2.0 available to it.) More bonus points available for maintaining clock sync across cards - i.e. allow one card to derive its master clock for timing the E1 or T1 ports from a different card. Any questions, please PM me. Thanks -- Dave