Some Osprey models have adjustable hip belts but I can’t find any info on their size range. The one on my Atmos AG 50 looks like it goes up to 42 or 44 inches. My Aether AG 70 uses an interchangeable hip belt and shoulder harness, as does my Argon 85, but that model of Aether has been superseded and the Argon has been out of production for a while. I was able to buy a hip belt for the Argon last year, though, but I don’t know what size range it fits. I have about a 40” waist and it fits me with a little extra.
Granite Gear uses adjustable hip belts with a range of 26-42” on their 60l models (Blaze and Crown2), and a large size that fits up to 52” is available. Perimeter (35l & 50l) also use these belts. They’re not available new any more, but their Nimbus packs (Nimbus Trace, NT Access, Nimbus Meridian, etc) are really great. They use interchangeable shoulder harnesses and hip belts, though L and XL are hard to find nowadays.
I have a few packs I’m looking to sell, a Granite Gear Crown2 60l in long torso length (21-24”), only used a few times; a GG Nimbus Meridian 60l with XL shoulder harness and waist belt, torso length 18-22”, pack is used but in great shape; and an Osprey Aether AG 70 that’s only been used maybe 5-6 times. I think it has L shoulder harness and waist belt and is for 18-21” torso.