Whoa, I'm not sure but why do you need 6 channels from a HU? What is the purpose? Are you trying to use surround sound? You're better off buying 4 or 5 channel external amp. It sounds 10x better with more power and cheaper too.
6 pre-outs yes. powered 6 chanel, not that I know.
most higher end units have 2 front, 2 rear, 2 sub pre-outs. most DVD units are 6 channel 5.1 pre-outs or 4.1 pre-outs and powered center channel by the head unit