Brand and Product details for all electronic items

1. I need to create a database of all the consumer and household appliances in the following sequence ---- Product category (e.g. Mobile Phones) --> Brand (e.g. samsung) --> Model No. (e.g. Note 3) --> One more detail form the product catalogue (to be disclosed later). 2. Need a mechanism by which the database is updated with new products 3. I think Flipkart, ebay, amazon etc. are probably the most updated sites containing about 70% of the products that I need - so this could be a good source.