What was the original issue with the brakes? Why change all for rotors and calipers? I ask because I'm leaning towards the master cylinder being the culprit, but a little more info would be nice before I tell you to jump in and spend more money. How do the brakes feel cold? nice solid peddle?, mushy?. Do you have to be careful when you step on them, do they lock up? Do you have ABS?
Answer a few of these and I think you'll start seeing your problem. If not me, and others I'm sure, would be willing to help.