I was also thinking a 24 hour turn game would be nice. Then I can just check in every day at the same time, no way I will find a good 12 hour routine for a few weeks. Probably would work if you just allocated more resources per turn with more initial resources. Regardless, looks fun.
The best way to do it will be 5-10 min. turns with option to end your turn before that. If everyone is ready than it's not needed to wait and just jump to the next turn.
I recommend a game mode where you can check a box and send a notification to the server that you completed your turn. If all 50 players checked their turn then automatically update the server move on to next round.