Do I have to go for the full 25% of child support for my 2 kids, if the father is carrying the insurance for them?

Child support is set by statute and the percentage guidelines based on the number of children to support and the non-custodial parent's income.  These guidelines are presumed reasonable.  It is not unusual for the court to order the non-custodial parent to pay child support and cover the child on insurance.  So asking for the full amount of child support set by statute and that he cover medical insurance is perfectly in the norm.

Even though these guidelines are presumed reasonable, the court can deviate if it is in the best interest of the child.  This occurs in cases where a child has special needs and would need more financial assistance.  The parties can also agree to a deviation from the standard guidelines.   For example, if the custodial parent has a better insurance program, many parents agree for the custodial parent to carry the children on their plan, and the non-custodial parent will agree to help with a slightly higher child support payment.

What you have listed to ask for is not unreasonable.  However, if there are specialized issues which affect your child or your finances, you can make a request for the court to deviate from these guidelines.  What is reasonable will depend on what you are able to verify to the court.  It's not enough for you to suggest that your child has specialized needs--- you would also need to produce receipts and historical documentation (like a medical report), to demonstrate that the higher child support obligation is warranted.  The judge can't grant you a "windfall," but can order higher child support if verified.