We'd have to break up a good chunk of our core because getting those players are going to need trades and the cap would not work without giving up all of our role players that really play a big role in making a title team.
Hayward would be signed to a max in 2017 offseason ( no idea why Jazz would not match but who knows), so that makes two max contracts on the team (Hayward and Horford). With Bradley, Thomas, and Smart all needing pay raises in 2018 offseason (same as Cousins) the team would have to move on from one or two. It is unrealistic to have three max contracts let alone try to add 4 to one team. So either Thomas or Horford would not fit if Cousins and Hayward are added. The same goes for Bradley (He's looking to cash in at 20M at least).
With all that cap pieces to fit together, it looks that trading some our core pieces that are due for raises might be the best options. This ultimately makes making that team super unrealistic (although it would be pretty [dang] good). I do want to point out that a team that starts Smart, Hayward, Crowder, Horford and Cousins would still probably win us a title and keep us competing at a high level for at least a half a decade.