Amazon has opened pre-orders for the 4K Ultra HD version of 300. The bundle also comes with the Blu-Ray and digital versions of the same movie. If you are interested, you can pre-order with the following link from the online retailer:
You can also check out what the packaging design looks like for the physical 4K release of 300 with the image located just below this paragraph.
According to the product page, the 4K UHD Set will be coming out on Oct. 6, 2020, in the U.S. region. 300, which was directed by Zack Snyder, originally came out in theaters in 2006.