The Mothers one comes with 2 pads I think. To buy the pads alone here in Australia is very pricey (Meg's wants $30 each for the 6" ones). I get mine from Exceldetail.com for US$9 each + shipping (which is usually 3/4 times the price of the item).
I use the Bosch PEX400AE. It has a 125mm backing plate and 400W rating. It costs $140-150. But even though it's powerful, it still takes a lot of time and effort for swirl removal.