need help with 5 channel amp

I have paradigm studio 100s and I am in desperate need of an amp. I am looking at the Parasound 2205, anthem mca5, ATI 1505, and the outlaw amp. I am on a budget and will buy used. The ATI worries me because it only has 150 watts and I think I will need more power then that. I am sure the parasound is the best but it also is the most expensive and I would have to buy it used. Also I liston to 2 channel music a lot so which one of these amps would be best for that. What would you all choose.