If you want to go with the 24458, get 'em now. Purolator has superceded them with the 14459, which is the same size as the 3593A, and has about half the filter media area as the 24458 (appx 100 sq. in. versus about 200 sq. in.).
Once the current stock is exhausted, that's it. You could also try the 14619, which also has about 200 sq. in. of media area, but is bigger in diameter than the 24458 or 14459. I spent a couple hours running around to some of the local Pep Boys buying up their stock of PureOne PL24458s.