First of all, all spots here (for other readers too): http://se.kiteforum.com/spots
From what you want I think Lagoinha is your best bet.
Few kiters and lots of space. Also nice Kicker waves and excellent waves in general. Winds are few knots stronger than Cumbuco. Sweet little town.
Cumbuco changed, but to the good. Great dining with lots of options. And lots of space on the ocean.
Why not do a few days Cumbuco, then Lagoinha.
If you want some nightlife, then Cumbuco or Jericoacoa.
Don't go south of Fortaleza, winds will be lighter at this time of the year.
If you want flat water, ocean, consider Atins as an option. Long drive from Fortaleza though. Guess Sao Luis will be closer, but no international fights from what I know.
Maybe also check out Tatajuba as an option, just after Jericoacoa.
Hope it helps!