Booking J1 to USA without USIT etc

EDIT: This was originally in the main travel forum. It was moved here. Didn't know this forum existed, looked around, found my answers, thank you.

Hi, just a question to people who will know a lot more about this than me.

My friends and I plan on heading to the US for a J1 next summer. I don't really want to go through USIT as I reckon flights, insurance and all the rest of it would work out a lot cheaper without them.

Does anybody have any experience with booking a J1 by yourself? Any ideas of the steps involved? Any information at all would be a massive help, thanks in advance!