Hello,
If you are not experienced with dealing with this power levels, it would be foolish to even attempt what you are trying to do.
Thats why most of the people are keeping mum. Noone wants to help you build a device with which you can hurt yourself, or worse, hurt others.
Like it goes in the common saying, "If you need to ask the price, you cant afford it"
If you need to ask how to achieve this levels of power control, you are not obviously equipped to handle it.
I am sorry, it is unlikely someone will even want to give you any help beyond what others have already done.
Get off the shelf components, work with them. They have many built in safety features that you might not think of, need, use, imagine or build into your DIY system.