A lot of ideas work for DFS because of his relatively small salary.
For salary purposes (adding whatever picks you need) you could do:
1) Huerter straight up for DFS
2) Davion and Duarte for DFS
3) Davion and Javale for DFS
4) Davion and Sasha for DFS
5) Huerter and Davion for DFS and Royce
Some of these would obviously need more picks, but they could take Huerter as a plug and play shooter, Davion and Sasha as prospects, or they could take a swing on Davion and some cap relief in the form Javale and Duarte who have much shorter contracts.
If you did the first, you might be looking at a jumbo rotation
Sabonis/Len or Javale
DFS/Lyles
Barnes/Duarte or Kessler or Colby (10th man probably not in the rotation)
Keegan/Monk
Fox/Davion or Keon
Keegan's ability to track guards, and DFS' ability to match up 2-5 make this a workable lineup, and even though DFS isn't the shooter that Huerter is, he is definitely a threat. Plus, you have plenty of offense off the bench with Monk and Lyles, and can still go small with multiple of Fox, Davion, Keon, or Monk in at the same time. You also would still see a lot of Keegan at the 3 and 4, since all of these guys can play multiple positions. Tons of flexibility and length on this squad.
Or if you got them to go for a non-Huerter trade, you could go with something like
Sabonis/Len
DFS/Lyles
Keegan/Barnes
Huerter/Monk
Fox/Ellis
Again, plenty of versatility and flexibility since DFS and Keegan can both guard multiple positions.
I kind of like the idea of the first. Keegan as a 2 unlocks a lot of potential length, defense, and rebounding for us. If he can stay with guys like Steph, Shai, Booker, etc... then he can presumably play 20-24 minutes at the 2 each game, and then sliding to 3/4 and letting Monk play the rest of the 2 minutes in a more traditional looking lineup (especially if you need another ball handler/guy who can create offense). But that first lineup makes you very dependent on getting your offensive initiation from Sabonis, Fox, Monk, and Barnes, without many assets to add more offensive versatility.