IMO:
Are you looking to be the one doing the organizing, such as being a TD? If so, do a weekly or "Pop-Up" tournament. Stay away from the leagues. WAY more work and drama for you.
The Pop-Up style gives you freedom if you want to skip some weeks, and also freedom to change the format some weeks. For example, I do handicapped 9 ball 90% of the time, but have also done 2 open 9 ball events, and one open Banks event.
If it's a weeknight, do single elimination. Double takes way too long. If you must do double, do super short races, such as 3 winner's and 2 losers.
I don't recommend 10 ball. It's hard as hell to make a ball on the break on a 9', especially with a triangle rack. It's absolutely nothing like SVB's break on the local level, even with 600 speed players. The players are playing with 10 balls on the table after the break. Takes MUCH longer than 9 ball, where 1-2 balls often goes on the break, and 7-8 balls are left on the table.
I'd recommend magic racks too. It makes the game play go faster (less clusters, more chance to make a ball on the break), and the racking go faster. You'll have to bring your own, and take them home in a folder with you each event.
If no one is doing FargoRated tournaments in your area, that will be a good draw if you do it. Can be handicapped or open, but if its reported, people will want to come to see how they stack up.
Don't do any skill capped events. They punish anyone who gets good. If you have low participation because the same person keeps winning, then switch to a handicapped format, or a mix of the two.
You must promote it every single event. FB calendar event on your page. Invite all your FB friends, and tag the pool room. Plus, post it in the local FB tournament announcement groups in your area. Plus, flyers on clear plastic stands throughout the room.
After the event, you must do a short summery write up, and post it in all the FB places you originally announced it. This will keep people coming back, and attract new people. People like their names in the spotlight.
These are my experiences becoming a "pop-up" TD since December. I have 16 tournaments under my belt since Dec 1, and have had a fun time organizing and playing in them. It is a lot of work to put together. I do it for free, so I have a tournament to play in that suits the format I prefer.