Single elimination is brutal, as nearly half of your players will be eliminated in the first match, which is a very short and unsatisfying experience for those players.
The key factor which you failed to mention is how many tables you have to play this tournament on? Hopefully you have at least 8 tables?
The other factor you didn’t mention is whether or not you will be handicapping entrants? That is an entirely separate thread in itself, but certainly one that needs to be seriously considered if there is a large range in the skill level of the various participants, if you want it to be fair and more enjoyable for all. Of course to do that, you have to have a pretty good handle as to the skill level of all the players.
I’m not sure what the skill level of your players are as to how long each match might take, but I would recommend a double elimination format, with races to 75 in the 1st round and subsequent rounds on the winner’s side and races to 50 on the one-loss side all the way through, which will significantly speed up the tournament.
Double elimination tournaments are always extended due to matches on the one loss side. Depending on what time it is by the time the semi finals (one loss finals) match starts, that match could be extended to 75 points as well. The tournament finals should be a single race to either 75 or 100 points.
This format for up to 16 players (and I would strongly advise cutting off entries at no more than 16) if you have 8 tables to play your matches on, would take 8 rounds to complete. Assuming each round averages taking roughly 1:15 - 1:30 max, you should be able to finish the entire tournament in 10-12 hours. If you start by 11 AM or noon, you should still be finish at a reasonable hour, certainly no later than midnight.