Will be lucky if Sacramento pick is top 5 let alone no. 1.
I think Davis to Celtics happens within the next year. Ainge is obsessed with him, the only issue is he usually tries to lowball teams and Pelicans won't take a second rate offer when they know they can have some of Brown, Smart, Rozier and all the picks Celtics own (Tatum will be off the table).
I can see something like Hayward, Brown, Rozier, Sacramento pick and Memphis pick being an offer. Lakers will probably try to compete with that with Ingram, one of Kuzma and Hart, salary filler and picks. Celtics offer, if it is that, will be more enticing though as if you are starting a reboot you want young players (Brown, Rozier) as well as picks to have a good start. Hayward would be a salary filler but a valuable one - they could also add Smart instead. Celtics would then roll with Tatum, Irving and Davis as their core. Knowing Ainge though he will probably try to not include Brown.
Sixers were on the list of teams Davis would consider but they don't have a way to make an offer, an Embiid/Davis frontcourt would be unplayable though. Clippers would be my outside bet but would find it incredibly tough to make a compelling offer and would probably need to wait until 2020 free agency.
Green + Iguodala would not even get you McCollum.