As I said above, if your daughter sponsors your son, then it takes more than 10 years and that is not a good choice at all. The best choice is that you become a green card holder, then sponosr your son.
You and your son can enter US using the B2 visa, then your daughter can file I-130 and you file I-485 concurrently, but you need to wait for at least 90 days after you enter US to do that. Otherwise, the I-130 and your I-485 will not be approved due to the 90-day rule limitation.
Your son then can extend his B2 status again and again until you get the green card to sponsor his green card. Because your child is a minor (less than 18) who needs your custody physically, he should have no problem to extend his B2 status again and again.
