If you are using a Sansamp in line with the GK, then "your sound" is a combination of both. If "your sound" is just the Sansamp, then use its DI. If "your sound" is just the GK, then adding a Sansamp would be a mistake.
Whether to go pre or post EQ on the GK depends on how much your sound depends on that EQ. For example if you use dramatic EQ changes for super dubby or scooped sounds, then you want those to go to the PA, right, so you'd go post EQ. OTOH if you mostly just use the EQ to adjust your rig so it sounds decent on different stages or in different rooms, then for the PA you should leave those changes to the soundman, and send him a pre-EQ signal.