Awesome idea, hope the netcode is solid to be able to include people outside the US, or if there's enough interest maybe even have another event to sponsor EU/MiddleEast players to go as well.
I've ran online tourneys before and it's a bitch sometimes but it's very doable especially if there's an entry fee and/or a stream, gives people a lot more incentive to show up on time and not bail out.
Like people mentioned it can be also done like R/Kappa, or at least give the event a name that the winners will have to use in their handle to give it more awareness like "TestYourSalt|B.Shazzy" or whatever. The shirt idea to get donations is great as well.
Lots of potential in this to get more people out to events depending on how it's done. I'll be glad to help as well if there's anything I can do.