Suicide Squad 2: 10 Comics James Gunn Should Adapt
2. Secret Six: Unhinged
They may not be the Suicide Squad, but the Secret Six are just as good. Deadshot is a key player in both teams and with the Fresh Prince playing him, he works better as a hero more than as a villain.
The basic premise of the Secret Six is just that: they're a group of mercenaries who will do any job, good or bad, for the right price. However, a storyline that could work whether or not they go the Secret Six Route takes place in the first seven issues of the Secret Six ongoing: Unhinged.
In the comics, the Six are hired to break Tarantula out of jail and find an onyx black card that every villain is scrambling for. It is the mythic Get Out Of Hell Free card, and there's a hefty bounty put out on each of the Six to reclaim it.
Adapting that to be Waller sending the Suicide Squad for it due to her own personal issues would work just as well, and if they can work in the Six too, it would be even better.