There is great potential, but I usually would say to steer away from the space marines and SoB as they are a bit too erm...uptight.  You can do amazing things using the stuff from Rogue Trader though.  The eponymous Rogue Trader, striving to make a proper name for himself and his erstwhile and entrepeneurial cadre of misfit ne'erdowells drawn from the dredges and heights of Imperial society.  Or you could have an arbitrator team, and have a Judge Dredd style campaign of attempting to bring The Law to a hive city.