You need the map to be huge.
The speed and gravity need to be fixed too.
It's gonna be a lot of work but it could work
also, a league off the bat might be a little much... I would suggest running a server with the speedball and see how it goes, even if it's god smackingly glorious, if nobody knows about it/it's not popular, a league is gonna be hard to set up.
Good luck with it though.