The construction will be interesting. There are a ton of small guards who are seemingly interested (Kyrie, Lillard, Trae, Fox, Garland), but should you take more than one (Steph)? Those guys get targeted and bullied in high level FIBA. It probably makes more sense to roll with only Steph, and then have a bigger point like Halliburton or Jrue backing him up
In regards to which three centers you bring, that can't really be answered until you know Embiid and Davis's statuses. Bam should be on the team regardless. Draymond will probably be on the team since Kerr is the coach. If there's a spot open, you then look at JJJ (he's much better as a third center who you don't have to rely on heavy minutes for) or even Chet, who figures to be a great fit for FIBA if he progresses
Then you take two shooting/combo guards in Booker and Edwards, and fill in the rest with wings (KD, Lebron, Tatum, Bridges, Butler, PG, etc). You also consider Reaves since he's a ball mover who can shoot
A couple of wildcards are Zion, Kawhi, and Mobley