Very doubtful you will find it in that size. As far as I know, the sole source for 1084 is the New Jersey Steel Baron..... and he has had it made to order from Germany since the U.S. supply was exhausted. All the U.S. mills that produced it shut down over a decade ago.
I suspect you're only avenue would be to purchase what you can get and forge, or have it forged down to that thickness.