Thanks for your answers guys!
I checked at Sparkun. They have what they call a "Arduino Stackable Header Kit - R3" (Arduino Stackable Header Kit - R3 - PRT-11417 - SparkFun Electronics) which they sell for 1.50$US. I would lack the 6x2 ICSP header. Also, I don't need the long pins (Stackable). I guess I will have to cut them. (I don't see a "header kit" with short pins).
Problem is, it is backorder.
Adafruit sells the "Shield stacking headers for Arduino (R3 Compatible)" (Shield stacking headers for Arduino (R3 Compatible) : ID 85 : $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits) which is pretty much the same thing for 1.95$US and they have it in stock.
They both carry the DC connector.
I checked "Rugged Circuits" but I can't find 10 pins headers. They I missed something?
You are helping very much. Thanks again.