WooCommerce Product Feeds

Hi,

I am using WooCommerce to build an e-commerce site (www.firstrateblinds.com).
Our company sells various types of window coverings in countless size options (ie: 24 x 32 1/2) and I need my site to have the power to offer the size options in a drop-down and also price products according to their respective size.

I have created product feeds in Excel that have a row for each variation (size, length, width, etc) but I have not been able to find a plug-in that will allow me to upload the document and create the drop-downs and price grids.

Any advice for a plug-in to do this?

Thanks in advance!