First thing to check when brakes are wearing unevenly like you described is the sliders that are in the caliper. These are located where the bolts that hold the caliper to the caliper bracket are and slide within rubber boots. These as well as the boots themselves go all the way through the caliper on either side of the caliper piston. Chances are that you have one or both of these rubber boots damaged and the sliders are hung up in there. These type of brakes (single piston) require that the entire caliper be floating to equalize the pressure on each pad. To make this happen the sliders must 'slide' without hanging up in the rubber boot.
You should probably get a new set of rotors, pads definitely, and carefully check and clean the sliders. Also, when you get to putting things back together get some good quality "Disc Brake Grease", which you can find at any auto parts store. Put a liberal coat of grease on the back of the pads as well as the mating surfaces of the caliper and piston and try to get a lot of the grease in the rubber boots before you put things back together. The sliders will feel very tight because of the viscosity of the brake grease, but once the brakes heat up they will slide very nicely.
Just a recap here. First thing that I would check is the sliders. You may want to see if you can get your rotors turned, but as specified in an earlier post, once you turn a rotor it is only a short matter of time before it wears out again. Your best bet would be to get a new set of rotors to save some time and money. If you use the grease then the type of pad really doesn't matter as this will dampen out any vibrations that may be created from 'metallic' brake pads.
Oh and another thing. When you go to push the piston back into the caliper (before you put the new pads in) you should loosen the bleed screw and put a piece of vacuum line on it that fits tightly then place the end of that line in a jar or cup with some brake fluid in it. This is because anti-lock brake systems don't like fluid forced backwards through the system. It tends to mess things up (or so I have been told). It is just a good practice.
Good Luck
