Factory Aimpoint, M4, I have seen them for about 760-800 at the cheapest.
The combo that Larue sells is $804 with the LT mount. The M4S is a little cheaper.
try g&r tactical they have combo deals.
My wife ordered one for me from Botach. It was substantially cheaper than anywhere else, however, it has been backordered and is not here yet. With their past history we’ll see if it was a good choice or not. Price was very good, if delivery happens.
G & R for optic only.
Larue if you need a good mount.