(cut) >Maybe a better approach would be, if you are thinking about low level stuff, >to use FPGA or so, but again, it's expensive. (cut)
Small note: The RME Hammerfall DSP cards are built upon a Xilinx FPGA. But I don't think they have their implementation openly available :) They use Xilinx FPGAs at the exercise sessions for Digital Electronics and Processors at ESAT, don't they ? Maybe they could lend you one when they don't need them themselves. Provided you took care of it :) best regards vini PS: I don't do electronics, but CS :) (so I had DEP as a course last year)
