Oh, I'm not that experienced. But I've done tons of research.

I've heard that bumblebee gobies would work great with them. I've also heard that figure 8s are a bit more docile, but they are still puffers

You've just gotta be careful. My gsps are living with mollies, and they don't bother them. Just remember that they get more aggressive as they age. But a 15 gallon will not be able to hold a fullgrown puffer. They will need more like 30. I have mine in a 20 right now, but when they get bigger I'm going to get at least a 55 for them, or maybe 2 30s if they won't play nice together. I'm not 100% sure on this, but I think the figure 8s stay a bit smaller than gsps. It just depends on the temperament of the fish whether they'll let other fish stay with them or not. Just make sure to add the gobies first. I think that with overfiltration, staying on top of those water changes, and keeping a close eye on those gobies, you could have quite a successful set up there, although you probably should upgrade when the puff gets larger.
