Tier 1 ET dependent visa

Hi
I am planning to apply for a dependent visa for my wife and kids after one year from my 3 year ET visa. I would be very grateful for answering me the following questions

1- Is there an application form to download, as I found only forms for tier 1 (Entrepreneur) and (Graduate Entrepreneur).
2- Do I have to make a separate application form for each individual (Kids are under 18 year old)
3- How many years should I apply for them, my visa will be expired in 2020.
4- What about the fees, do I need also to pay visa fee for every one of my kids

Thanks in advance for your kind help and support.