Unfortunately you can't. A lot of the "locked behind paywall" stuff was opened up when they removed the marketplace for Classic, but not all of it.
The crafting kit is one of the casualties. You'll have to make due with the separate crafting kits.
"Invisible" wardrobe items are another problem. They DO drop very rarely from big bosses/events (at least I've heard that they do), but good luck assembling an entire set.