Design a Custom Database System

Hi I"m looking to design a Custom Data Base in Visual Studio or similar Software, I Have many ideas what I want to be able to do and what kind of actions id like to add, but I'll take it step by step and keep on adding to it as we go. I would like to start by building a Data Base of all products that we carry, I have 1 item description but the very same item is being sold under a few different SKU's so id like the system to recognize them all as 1 item, I have CVS reports that I download from 3rd party websites, so id like to setup a system how I can easily upload this file in my system and it should get all the info in the right place. I want to the system to be able to check for pricing online (specific website) so I'll have the SKU and the system should go online and retrieve the current price. I want to be able to apply actions for transaction done at a specified period of time, I have many many more things that id like to do but this is to have an idea what kind of work I'll need Will extend working Hours and $/hour as things start moving. Please send your proposal only if you feel you can do all this work. Thanks