Given that WP already has good Amazon integration via plugins like CG-Amazon, I can't say I've heard of mrrat's scripts being used. If there's something lacking in CG-Amazon that you critically need, I'm always happy to add features to folks who donate. :)
Pages are written using the Write panel (Posts, then Pages). Pages are just Posts that are 'classified' differently in the system. Generally anything you can do in a post you can do in a page. Additionally, a page can be mapped to a custom PHP template file for just that page's display.
CG-Amazon (with the help of CG-Inline and/or CG-QuickPHP) can be used to embed a given ASIN (or a dynamic query) within sidebar, post, or page, and caches results locally for performance -- this means you could do a given lookup/query on say 10 items (or a keyword, whatever), and ask for a random selection of 3 to be displayed, and CG-Amazon will cache the original 10 on the first call, and then locally return a random 3 each subsequent call (until the cache timeout comes along...).
Styling control admittedly needs to be reworked a bit (on my list), but otherwise CG-Amazon gives a TON of power.
CG-Amazon combined with a custom template can actually give you an 'almost-store', as my complete custom (WP-not-needed) sample in the CG-PowerPack shows how to iterate through your local database of ASIN items and display them in a list, and display them individually.
Check out http://www.chait.net/cgaindex.php as an example of a listing, or many of my reviews which generally have an embedded 'live' amazon callout in them.
Let me know if you'd like to try it out.
-d