The second band cuaght my interest far more than the first one its got to be said, but its got to be said that i didnt consider any of the songs you poted to be the kind of music I would class as progressive. Kinda in the Animlas as Leaders, but certainly not in Periphery...not to say theyre a bad band.

Checked out Ayreon?? Theyre a prog metal project, brilliant examples in there of what i would consider as progressive, but, i suppose, with a gernee like this, theres no real set rules to take from
http://www.youtube.com/watch?v=tIqRsl8Vm-Q - Age of Shadows
http://www.youtube.com/watch?v=ebHbuL3l12Q - unnatural Selection
http://www.youtube.com/watch?v=c-ncSNUswVY - Day 3 - Pain

Admiteddly, the songs don't make much sense without backstory, since they all fit in together as a single story, across all the albums, but there are just sings to give a Taste

Got to thank Davis / Nocturnal for getting me into them, but i just love them so much that heh...