Something like a Peak Design Sling bag might be what you're looking for? I doubt you'd find a chest bag big enough for that combo. A Peak Design Clip apparently has a weight limit of 90KG so it should hold that camera and lens easily.I'm looking at getting a chest bag for my Sony A7RIII whilst hiking, I don't fancy hanging the camera and tamron 50-400 from a peak design clip, can anyone recommend a chest bag please?