2 subs is definitely the way to go, and they won't overpower you once calibrated. Dual subs results in a smoother frequency response, which yields better impact and deeper extension (a very good thing).
Speaker wise, the Focal's you are look ing at are nice speakers, but I'd definitely give...
Hi Siddhartha,
I would suggest going with the SB16 Ultra over the 13, as it's a new and improved design.
Do you have a budget in mind for the whole system?