Ebay might be your only recourse. Or go down to your local ATV shop and see if the mechanics know of any shop in your area that buys wrecked machines to part out. Also if you see a person that has a number of parts available send them a message and see if they might have what you need.
Here in western Colorado we have a shop like that in Grand Junction, I believe that their name is Motorcycle Accessories. It has been quite a while since I was there but I think they are still around.
Other than that you might need to find a junk machine and take off what you need and part out the rest.
Also have you talked to a welding shop to see if they can repair the A arm, that is if it isn't too destroyed.
Not sure where you're located, but here in Minnesota there is a company called 'Crashed Toys' that buys anything outdoor recreation related that has been damaged. A quick Google search shows they are located in multiple states so worth doing a Google search in your area.
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