Just ordered Thunderstone AEG, need to know what color and how many boxes of sleeves i need from FFG. Thanks in advance.

Using my necromancy skillz on this thread, because I just got Thunderstone myself.

The core games comes with 530 cards, 5 of which are just turn order reference cards, 32 are XP. These aren't shuffled or handled much, and a later expansion replaces the XP cards. So 10 packs of the grey sleeves will be enough, and fit snugly around the cards.

However…I don't really recommend sleeves if you want to fit everything in the boxes. The first expansion adds dividers and a better design to hold the cords, but it's smaller. Sleeved up the first two expansion could be too tight. I'm hoping for a giant-sized expansion box with the next one, accounting for sleeves

There are no problems sleeving up the first two expansions. Sure, it will be tight, but it will fit the box with a little spare room. This is however done with "penny sleeves", but don't think there is any problem with it.