re: What would be the best account to open to save for your kid(s)?

If you are looking into a brokerage for a minor child, you'll probably get steered to a UTMA.

We created accounts as soon as our little ones had their SS#s. We put about $1k a month in each account each month and use the funds for their current tuition, and savings for college. When all is said and done, we are basically using it as a brokerage account to put tuition aside and save about $3-4k a year towards college.

Can use the funds to cover any expenses for the child
You have to start filing returns for your child on their own, as any income earned is at their tax rate.
Usually, a con for the accounts is once they hit 18 in most states, the accounts automatically transfer to them. But sounds like you're looking to do this anyway.