Cassian can create a lot of exposes with his grenade and hits really hard and is a pretty good killer.
I was thinking Jyn Chaze CLS and Raid Han. Raid hans buff would be a pretty nice heal as it gives 3-4 buffs. Maybe Pao and take out Chirrut? He grants offense up and would heal, and his grenade adds defense down and another potential expose. Or Cassian for the reasons stated with his grenade.
Let me know how it works. Assuming you have Jyn zeta? Also Jyn lead gives potency buff, so I would go full damage mods.