The AGOAC and Starter box have the new minis. If you don't have those yet, they are nice.
https://smile.amazon.com/gp/product/B000AZBDBU/
https://smile.amazon.com/gp/product/B000AZD0U2/
Past that, they also have rule books, novels, and map packs.
Looks like they also have some of the new clan invasion stuff.
I've been an avid reader of the Battletech books and played through all the MW games on PC, along with the Mech Assault 1&2 on Xbox. I wanted to try out the tabletop game myself so I recently purchased the Beginner's Box. Check it out. There are a lot of expansions to the tabletop game with more mechs and scenarios.
Battletech Beginner's Box - Amazon