I found the 2.5" wide weather strip on the following web page. The price was considerably higher than what another vendor told me it should be but it was the only place I could find it. 25' roll cost me $38 with shipping.
Web page:rv-trader items - Get great deals on RV, Door items on eBay Stores!
Aubry's in Yakima Washington has the smaller hollow weather strip with ribs on it. I bought some from Caroline and she was very reasonable. She just didn't have the wider weather strip that I also needed.
Hope that helps and if you find a better place to buy the wide weatherstripping please let us all know.