RTV 900 seatbelts - where to get?

I need to replace the seatbelts in my 2006 RTV. Some time before I got it, the originals were removed.

It looks like they attach with 5/16" (or equivalent metric) bolts, so generic seat belts would work fine.

If you wanted new-ish seat belts for your RTV without paying lots of $$$, where would you go?

Thanks

RTV 900 seatbelts - where to get?