Watch out for AMX5.1 with eL84, at 15 watts x5. Coming soon! You will need a DVD player with 5.1 outputs, we will not be building the decoder anymore, just the amplifier sections. I think the 15watts per side (Have tried the 2Ch version on my HT) is more than adequate in driving my 88 dB HT loudspeakers, and the amp does not produce too much heat on class AB. I am considering also the 6V6 and have tried it too, only it is kinda hard to get, unlike EL84s.
You are right, with tube audio you can watch 2 to 3 DVDs in a single sitting without listening fatigue. Your Sub can be any SS powered type.