One idea I had long ago was to build digital amp modules for the old Theta Dreadnaught line. Theta has already introduced a D version of the Dreadnaught though, here:
http://thetadigital.com/dreadnaught_d_amplifier_info.shtml#
Best,
E
http://thetadigital.com/dreadnaught_d_amplifier_info.shtml#
Best,
E