I own a pair of Mirage M5si speakers. I can't find the exact specifications online, but some thorough searching has shown me that they have nominal 6 ohms with 4 ohms capable. They operate between 70W and 200W.
I'm looking to replace my current receiver and amplifier with a receiver that will be able to do both jobs at the same time. I don't have the model name for the receiver. My current amplifier is an Adcom GFA5400. Both the amplifier and receiver that I currently own are quite damaged.
I don't know about those speakers. My system has three 4 ohm speakers in front and 6 or 8 ohm ones elsewhere, mostly Axiom. I just got a Pioneer SC-1522-K, which is just in your price range (discounted, from Amazon), and it seems to be handling my speakers perfectly well.