I think you may be over thinking this, Winterclaw.  IMO, we should consider a mission to Mars as a first step towards colonization.  If so much time and effort is going to be invested into such an endeavor, then why not make it a one way trip.  Launch unmanned payloads to deliver consumables, ship containers and habitats on the Martian surface.  Create solar-wind powered behemoth crafts to sail between worlds and settle permanently into Martian orbit.  In the end, those inhabitants will become a separate autonomous world with very little ties to it's home world.

For anyone interested, read Stanley Robinson's Red Mars, Green Mars, Blue Mars to get a perspective on Martian civilization development after the colonization by humans.  It offers an interesting and complex view on interplanetary survival and evolution.