no way are you serious?!?I don't have any experience with the others but scratch the CD5000 off your list....8V is what they advertise on the faceplate but it'll only do 5V before it starts to clip, at least that what mine does. Inside the users manual it's even published as 5V, so it might do 8V at full volume but it will be heavily clipped.
I'd like to know, too.may i ask why is 8v preouts so important?