brake caliper remanufacturer?

[Thrill91Si]

My left rear brake caliper came unbolted a couple weeks ago. I finally got the hardware to replace it yesterday. In looking at the caliper it appears that the piston might have overextended. Since it wasn't against the rotor any more and one of the pads fell out of the way the piston and one brake pad pushed all the way against the other side of the caliper.

I am assuming it is overextended since it doesn't seem to want to push back in. I used a big c-clamp and was really cranking down, it didn't move at all. It also looks a little angled, but that is hard to tell.

Is there a way to push the piston back in? Can I bang it straight or do I have to start looking for another caliper?

Along those lines, what is a good brake remanufacturer? I was looking at the Advance auto parts site and there is 4 or 5 listed with varying costs... Raybestos, Cardone, Bendix, etc. Is it worth the extra cost to get a loaded caliper? I don't need a new pad, but all the rest might be nice to have.

Thanx in advance.