Automate ecommerce inventory via csv/xml feeds (ie. Updating Stock/Adding new products)

Hello Freelancer Community, I am looking for someone who has extensive knowledge in how to automate my ecommerce inventory feeds from several suppliers. This will include updating the current stock level of the products, and also adding new stock that becomes available. The suppliers we will be using provide either XML or CSV files that have all their products within it. The updates would either need to run once a day (eg. cron job) or update in realtime... Whichever is easier for the developer. Currently we are hosted with BigCommerce, but I am very flexible with the Shopping Cart that can/should be used, and have installed Magento, OSCommerce & Joomla/OpenCart with several other self-hosted platforms on our dedicated server [just for testing purposes and to make sure it could be done]. I have also tested and used 3DCart which can be the platform if needed. The server currently running on Windows Server 2008 R2, but I would be willing to install any flavor of Linux if this would make it easier for the developer... As I said, I can be totally flexible just to make sure this can be done efficiently, cheaply and working 100%. However, I would need the ability to grab a csv/xml feed from the shopping cart so I am able to import the products to Amazon and GoogleBaseFeed. (which I know is very easy to do and most shopping carts have export solutions that provide this ability to port to a template [including BigCommerce who I am currently hosted with] - so it's not essential). The developer must have access to some sort of IM (ie. Skype, IRC, AIM, MSN or something along these lines). The budget is very tight and I have seen work like this be offered on freelancer for $150-300, so please no astronomical bids; although I'm open to all fair offers. I look forward to working with whoever wins this project.