PSA doesn’t seem to stock such an item only the stainless option.
Nevermind I knew I was missing something AR10.
Best bet is to buy a stripped upper and build your own. As there is not an ar10 standard it is best to buy same manufacturer for upper and lower.
I just realized you are looking for AR10 upper, not 5.56.
If you really want the look you can cerakote the barrel.
I’m not aware of any AR 10 rear aperture sights made for the AR-10 that will allow you to aim with a standard FSB.