Well now that we have more information, I don't see a reason not to go with the Santiagos. The other training offers no real benefits except that it will be less dangerous. Before this information post I was leaning that way last time anyway.
[X]: Train with the Santiagos. Requires three weeks. You will acquire items, skills compatible with the training received, 1 Basic Skill XP and 1 Combat Skill XP to be spent on current or acquired skills.