Free extensions for Joomla!

I am using a simple Shop front called I-Price Mini-Mart.
http://lot-studio.ru/en/iprice-minimart
I upload 1700 items every 3 hours.
I am having trouble getting Google to search the products on file.
I have written programs that produce an RSS feed using the website url and a filter to the product model number but google dosent appear to pick it up.
eg http://www.kbe.com.au/index.php/home?ifilter=SMU50E15AU
and I have listed the rss as a sitemap on goodle plus the sitemap for xmap.

Does anyone have an extention for I-Price ?

Any Suggestions?