Riveted should be in the Iron Marches at a heart dude, Helo Murkhaunt. I say this because the item description has a quote from him and the other items available include a trinket referencing the battle of Granite Front, so I'd check the heart guys around there.
I don't seem to be able to find "Riveted" armor set. I believe it is a Karma-bought set. I haven't seen "Commando" armor either. Both of them intrigue me a lot but I can't find them.
Commando is via story rewards only.