You would need to purchase Photoshop Elements 14 Mac and Premiere Elements 14 Mac as downloads from Adobe if you want to purchase from Adobe.
Adobe sells only the current version (14) and as download.
These programs are standalone programs.
Upgrade at Adobe is just a pricing term. Is it not one newer version updating an older version even on the same OS. Adobe Upgrade means that you get a lesser price from Adobe if you can show proof of purchase for a prior eligible version. This upgrade pricing is an Adobe practice which does not apply if the product is purchased elsewhere. If purchased elsewhere, the pricing is determined by the seller. Sometimes the seller's price might be lower than the Adobe "upgrade" price.
Also, you cannot open Premiere Elements Windows project files on Premiere Elements Mac. And you cannot open Premiere Elements Mac project files on Premiere Elements Windows.
Please consider. Suggestion is to look at the free 30 days tryout before purchase to assure the compatibility of the product with your computer environment and project goals.
Any questions, please do not hesitate to ask.