yep Lyndall Z-plus, they have them for your bike. the reason yours wore out so fast is,,,,,you ride the rear brake too much. happens alot on these bigger bikes, guys are afraid to gear down for fear of running rpms up too high. runnem up there and lay off the rear brake so much, I'm just sayin 
Another recommendation for the Lyndall pads, 7254-Z for the '08 and later Touring models.
http://lyndallracingbrakes.com/merchant/merchant.mvc?Screen=PROD&Store_Code=L&Product_Code=7254-Z&Attributes=Yes&Quantity=1I want to say this without ticking you off, but tact was never my long suit. It may very well be just as Larry stated, you may be riding that rear brake and not even realizing how much you do it. I've noticed lots of folks on baggers using the rear brake almost exclusively. Most of the braking power available, over 70%, is at the front. However, many people were taught, incorrectly, to rely on the rear brake because the front brake might throw you over the bars or cause the front end to wash out. I've heard that from people since I started out riding in 1965, and it's a myth that persists to this day. While that may have some validity for dirt bikes and trail riding, depending on terrain and situation, it's not directly translatable to street riding.
Of course, there is always a possibilty of a mechanical problem as well. If you raise the rear wheel off the ground and spin the tire, will it turn relatively easily or is the brake dragging heavily? If it's dragging heavily, you may have a sticking caliper/piston, a defective master cylinder, etc..
Jerry