Using Data Assist and API calls.

Sorry for the long post..
I have a few (20 or so) domains hosted on a shared server separate from my ecommerce store front site.
These domains contain just an index.html page and a few short paragraphs of seo content. All the outbound links on these pages (sites) are strictly relevant only to the products / categories they link to in to my ecommerce store. (www.turboboostgauges.com if that was confusing)

I want to started using these "splash / landing domains" (for lack of better terminology) as they are starting to pick up increasing organic traffic from the 3 major engines. Because of their keyword relevance as well as the domain names alone.
I have been finding (through G-Analytics) that these are also driving revenue as visitors are starting to convert more and more...

The problem I have with the sites is that my ecommerce provider supplies me only with a "remote add to card script." Which is just a form POST method and action that follows to the drop the appropriate product the customer clicks to their cart.

That's amazing!

But with 20+ domains and over 600 products it would be pointless for me to develope those pages using that script.

All of the product data that is important and essential to a visitor converting to a customer, (price, image, description, msrp) would all be static and then would have to be redone as soon as one attribute was changed.

However my provider does supply a public API.. I already have a token, but I do not know SOAP and XML to connect to it.

What I am hoping for is it that I will be able to learn how to script a connector application to dynamically "call" and return the current product information (price, image, etc) from the API and then use DataAssist to insert the called information to my shared hosting database.

Does it seem feasible or necessary even to go a couple steps farther and setup a MYSQL database (on the shared host)? Then develop a script that uses chronjob, per say, to periodically automate and crawl the inventory via the API for changes and updates. When it finds new / modified product info it would insert / update a recordset. Thus replicating my inventory to the MYSQL DB would allow me to have dynamic, current and up to date date product information all the time.

How would I go about starting this rather daunting task??

Any help would be appreciated..

Thanks in advance.