With the above in mind, I can't really see any big free agents out there that strike me as good fits with what we're doing (mostly based on age to be honest, OG is the only one from a quick glance but I'm not sure where he starts with Suggs/Franz/Paolo at the 2/3/4). So I think the most likely thing we do is extend Franz and Suggs to eat up any cap room we could have and then operate as an over the cap team.
If I had to guess I'd say we keep Mo Wagner and Joe Ingles (I'd be tempted to decline the option and offer him a cheaper number... That's a tricky thing to do without pissing someone off though, you'd have to have had a lot of conversations with him and his agent before hand so maybe you just pay him the 11m unless you think you really really need to cut a couple mil to stay under the tax).
Then since we'd be operating over the cap we'd have the 13m-ish MLE to shop with. You're not likely getting a starting PG at that price (maybe Spencer Dinwiddie I guess? Maybe? He might want more) and we're pretty set at every other position so maybe just go and get a wing, can never have too many of those, guys like Royce O Neal, Kyle Anderson, Caleb Martin, Saddiq Bey off the top of my head are all worthy of varying levels of interest I think.
I have no idea who of Harris, Goga and Fultz we bring back to be honest. I'd hope for Goga because this team really does need a decent third big with Wendell generally missing 20+ games a season. Harris and Fultz are toss ups I think at the minute. Id miss both but if you're bringing guys in (and developing AB, Jett and Caleb) you need minutes for them to play.
Chuma I'd be pretty surprised if he was brought back. Wish him well and I wouldn't be surprised if he carves out a role somewhere but I do think he needs a change of scenery to do that.