I do plan to pick up an EB trellis kit tootsweet in case anything does well.
With the growth an Earthbox provides, you'll need to get those tomato supports in place faster than you might think.
Several on this forum have noted that the EB trellis is well-suited to determinates such as Celebrity (or Roma) or intermediate short node (ISI) varieties, and that they grow shorter than or about as tall as the EB trellis.
I believe Supersweet 100 is an indeterminate (vining) tomato variety. It can grow to 8-10 ft long and may overwhelm the EB trellis, making the box top-heavy, or the trellis unstable, or both. Recommend you put concrete blocks against each long side of the EB to minimize tipover risk.