does anyone know other shopping networks to submit products to?
some of the few i know of
Google Merchant - Free
Yahoo! Shopping - PPC
Shopzilla - PPC
Amazon - Commission + Ref
eBay - Commission + Ref
There are many of them:
If you need a suggestion, I would suggest to focus on Amazon (or eBay) because it can give you many customers.
The Ukrainian company magneticone has been offering a good sortiment of feeds, for several carts. Their code isn't open source though.
Here is a link http://tinyurl.com/yaov9bf