The PLO under Mahmoud Abbas is probably the best you can get. He’s corrupt. And old. He’s not a zealot. He’s a pragmatist. But he’s not going to live forever.
However— none of these “orgs” need be in place, because of course none of them are worked the same way by Iran. So- no— none, not PLO, not PA, not Hamas, and not Hezbollah or any and all descended organizations from the Popular Front for the Liberation of Palestine (PFLP). Nothing, because leaving anything in place continues the bloodshed, and the perpetual hegemony of Iran.
Hamas is quite popular in the Palestinian Authority. As are the PFLP and PIJ. Presuming elections are held one day, the terror groups will win. No elections, as you say he's not going to live forever and it's unlikely he'll have a peace minded successor. Personally I'd forget about him and try to establish a moderate government in Gaza, no small task. Let Gaza be it's own state and see how it goes.