The regular grommets might work OK. I've never used them on a hipbelt, but I've used them on several packbags for external frames and they worked fine.

I recall years ago the Rain Shed would set them for you, or maybe let you use the tool. You might find a boat shop that would do that, as I believe they're used on sails and maybe other things. Someplace that sells canvas maybe also. Or a tack shop maybe.
Always remember that you are absolutely unique, just like everybody else. -Margaret Mead