Go with the Vortex Viper line to keep the cost down and yet still get great optics and lifetime warranty for under $500. Many options to choose from.I have ordered a Bassett mount for my M1a...the Standard High Scope Mount Package. I want to use a light scope, and 4X would be enough power for the kind of shooting I am going to do. Also, I don't want to pay too much for the scope, as the iron sights are mainly what I plan to use. They are usable with the Bassett mount, but of course I would normally use them without the scope mounted. I would pay the price for a Leupold at around $600 (which seems to be a price you can get), as I would prefer to buy American if possible. I am not sure if their Mk4 Tactical is suitable for the M1a. It seems that it is more for the AR15 type of rifle.