Add custom fields to the WooCommerce product page, and have them appear in the theme

Hi, I'm setting up a bookshop website with wordpress, a custom theme and WooCommerce.

I'm looking for an experienced wordpress/woocommerce developer who can:

1. create about 20 to 25 custom fields to the WooCommerce product page (who will appear either under the General tab (or better, in an additional tab).
2. Let appear those custom fields on my theme in the product page.
3. Deliver a pre-buildt CSV file which I can use to import about 10.000 books. Of course the custom fields should be enabled to be imported.
4. any changes in any php file should be documented, and the files should be delivered, so that in case of a rebuild of the site, I can simply place those customized files back, and know how.

I'm not experienced enough to start changing PHP files myself, but I did found a good description on how to do here: http://www.remicorson.com/mastering-woocommerce-products-custom-fields/

You can either work per hour or per fixed price, but in both cases I expect you to make a correct estimate.

I'm running my own virtual servers (digitalocean) and have full access to the wordpress site (I use ServerPilot and ManageWP).