I am a aimpoint guy, not a big eotech guy (furry sights) dont buy a clone because it looks the same, as a close friend one told me "we dont put toys on guns" and make sure that where you buy from is legit.
That is tough. Usually, you would consider a 4-8 power on the low side magnification to 12-25 max magnification. That being said, a scope with an AO in the 6-18 power range with good glass is pricey. Your best bet might be in a Bushnell Elite. They put a lot of quality into their scopes for the price and back it with a great warranty. I think you might have to up your budget a bit though.