BudsGunShop.com - Ar-Pistol

not the best choice you should look for on that is set up for a picatinny rail this would be a better option budsgunshop.com/product_info.php/products_id/712015420/trijicon+rmr+t2+65+moa+red+dot+adj+led+w%2f+rm33

Robert, you would need the pre mount attached version here for the top pistol Picatinny Rail : budsgunshop.com/product_info.php/products_id/712015420/trijicon+rmr+t2+65+moa+red+dot+adj+led+w%2f+rm33

It would work. You would need a mount for it. Easier to get something made for your pistol.

It would probably work, it is definitely a rugged and high quality optic although it is pretty small for this application and does not include any mount as it's mainly intended for optics-ready handguns and you would need a pretty high mount to get a decent cheek-weld and sight picture on an AR pistol.
I prefer Aimpoint Micro-style sights, the Aimpoint itself is very expensive but there are a lot of similar designs and clones that are at great price points. Personally, I own 3 of the Sig Romeo5 and really like them on my AR pistols. There are also similarly sized and priced options from Vortex, Primary Arms, Bushnell, Holosun, and several other brands I am forgetting.