Dear Faustini,
I think you are over-analyzing and over-thinking this decision. Why do you need the MSc or MA degree if you plan to get an MBA? Unless you have a solid rationale for how both degrees combined with your professional experience are necessary for your future career plans, business schools will question your need for two masters degrees.
As for when to apply, that depends on when you are ready. You have a competitive profile for your three target schools, despite the minimal extracurriculars, so I think you should apply in R2 if you want to be in business school next fall. There is no disadvantage to applying in R2 versus R1; you just want to get it in by the R2 deadline. Competitive, compelling applicants have a chance in any round, but there are few seats left in R3 which makes R3 a bit of a disadvantage.
Hope that helps. Good luck,
Lisa