I like the 2-sided 100% cotton terrycloth pads made by Argo & Co., (http://www.argoco.com) the people in Spartanburg SC who make Argosheen. You can buy them in any size you wish. I usually buy them in 16" or 17" sizes. You have to phone them to place any kind of order. Get the phone number at their website. They will ask you if you want the "filler" in them or not. ("filler" is some kind of plastic mesh they place between the 2 sides of terrycloth to minimize liquified soil from transferring thru to the other side of the pad.) I buy them with the filler. The pads will be something like $8 - $8.50 each, I think.
What size velcro do you need? I keep a supply of it on hand and can send you some at my cost. Same with the brush, which I pay about $5 for. Are you at the same Alisha Drive address?
Oops! I just re-read your email, and realized you were talking about STAIR pads, not the full size Challenger pads.
In that case, I would buy them in the 9" size. The price, however, will be about the same as for the larger, full size pads, since the small ones are made up as a custom order.