I definitely agree with what Byron said above, that it is certainly not necessary to have identical amplification channels for good HT. I was just stating the obvious "conventional wisdom" on the subject.
Perhaps some of the concern was that using amps with vastly different gains would make all channels harder to EQ, or if somebody ended up using one high-current amp paired with a less powerful amp, they may run into some clipping problems.
But with all the high-quality equipment considered here, this probably wont be much of an issue. The OP's system is going to sound great no matter what option he takes.
Perhaps some of the concern was that using amps with vastly different gains would make all channels harder to EQ, or if somebody ended up using one high-current amp paired with a less powerful amp, they may run into some clipping problems.
But with all the high-quality equipment considered here, this probably wont be much of an issue. The OP's system is going to sound great no matter what option he takes.