Regardless of your budget, I'd buy used - all the models you mention are fairly readily available used and you'll save a lot of money. Certainly, the Parasound and the ATI have been very well reviewed. I haven't listened to any, but from what I've read about them, I'd first investigate the Parasound. If you're interested in the ATI, they make a 250 w/ch version as well which is also regularly available used.
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.