http://www.alpine-usa.com/product/category/amplifiers
I really like the PDX models. I have two and I have no reason to use anything else. They run super cool, AND if you have problems out side of the warranty, $75 bucks, you send it in and it gets new parts and reshipped back to you.
The other nice thing as they are smaller, all the PDX are the same size and stack very well. They don't use a lot of energy. I've had other brands and roommates over the years and for example have had 500 watt MTX, RFG, etc.. and they all drained batteries quickly. Bass hits always made the lights flicker when the head lights were on etc.
I have an older PDX M5 that birthed at 87x4 rms and 325x1 rms plus a M6 rms 600 x1 and I could listen to the stereo at a reasonable volume w/ the truck off for several hours during my wash/wax. Never once drained the batteries and they always were cool to the touch even after road trips and such.
For the size and ability I have no reason to use anything else. There might be fancier amps or more powerful ones but at the size of a 8x11 sheet of paper find something else that will put out 1200 rms at 2 OR 4 ohm stable.
An M6 will give you more than 600 rms in a 2 or 4 ohm stable package and crutchfield and a few other places are having black friday deals. You can probable pick up one cheap with the holiday specials.