Thanks guys.
Has anyone used covers other than the 8701 for their SSP? When I checked the Weber section at Home Depot today, none of the various covers seemed to have their dimensions listed on the box, and I'm not familiar enough with dimensions of later model Performers to know whether or not their covers might fit the SSP. If I had a list of compatible covers (for the SSP) to keep handy I could be on the 'look out' for an alternative to the 8701 when I visit various stores or see them on sale online.
Maybe another approach to this is to ask if any later model Performers were as long, wide, and tall as the SSP. If not, then I suppose the obvious answer to my question as that no other cover can be used with the SSP.