No point in going for progressive scan. As the Hitachi uses an ALIS panel it is, inherantly, an interlaced panel.
I've done a number of tests with my 42PD5300 with an Arcam DV79 DVD playere testing with progressive switched on and off and I could tell very little, if any, difference with progressive switched on.
In fact, my wife, who knows nothing about this sort of thing thought the non-progressive picture was better every time.
DVI may give a better picture than component but, to be honest, component looks fantastic on my screen but I do have a quite expensive DVD player.
HTH
John