I'd really like Porter, but his salary is large so the team is clearly in the tax with him, and it makes matching salary difficult. That said I'd do Smart, Morris, Yabu, Bird, Wanamaker for him (once Smart can be traded in January).
Post-Trade 8 man playoff rotation and minutes
PG - Irving 36, Rozier 12
SG - Brown 36, Rozier 12
SF - Hayward 32, Tatum 16
PF - Tatum 18, Porter 30
C - Horford 34, Baynes 14
So total minutes
36 - Irving, Brown
34 - Tatum, Horford
32 - Hayward
30 - Porter
24 - Rozier
14 - Baynes
Now that is a team I think could truly compete for the title this year and for years to come. The rotation is much cleaner and Porter's elite shooting and defense would come in handy against the Warriors and top teams in the East. He adds a great dimension to the bench unit and is a great small ball 4 in the modern NBA.
I'd add some vet minimum type players, especially for the guard positions post trade, but I think that team could do quite well.