Sorry if I'm just being thick, because it was easy to set up a previous ADSL modem/router as simply a modem with 4 ports available to then attach two routers to. Are you saying simply get a 612 and unlock it, which will give two ports to which I can attach two routers to - I still only really need a modem, but with two usable ports to attach all my existing equipment.
As I say, please forgive me, but you seem to be suggesting that the 612 now needs to be setup as a router to get both ports available...