The XS system IS made for the AE, but if the rear sight dovetail is about 4" from the receiver, all you need to do is drill and tap two holes in the front ring of the receiver and remove the rear sight. I'm making my own from a weaver style scope base and a dovetail insert. Both were ordered from Brownells two days ago.
I'll still have to have the receiver drilled, but my idea will cost about $20 vs. $55. Of course the drilling and tapping is extra, but would have to be done either way.
I'll mount a red dot scope when complete.