Hi,
I am Nallakumar. I have more than 9 years of experience in C# and Outlook Applications.
Please have a look at my past projects here to validate my expertise in this area.
I would suggest the following solution,
1. We will develop a Outlook AddIn using C# and VSTO
2. The AddIn will create a button in the Outlook Ribbon. Upon clicking that button will show a screen, that will be used to Store Outlook credentials.
3. The AddIn will do the Sync from Google to Outlook using Google Contacts API to Sync Contact Categories and Contacts (and linking the Categories to it) every 5 mins. This will do Addition/Edit/Delete during that time.
4. When a New Contact is created/Contact is Edited/Deleted in Outlook, it will Sync immediately to Outlook using the APIs. Similarly the Categories also.
My bid is for the above solution and I can give you a first version in 3 days after you assign the work to me and creating the milestone payment. And then, I will do necessary testing/bug fixing and give you the final version.
Thanks,
Nalla