Integration and managing multiple stores

Good day,
I need some help to start planning an integrated Nopcommerce and asp.net web application.
I am part of the development team and my customers intention is to develop:
a. Multi store installation of nopcommerce. i.e. a number of shopping carts for different stores
b. Asp.net application that will manage various buyers and their accounts
c. From asp.net app I will need to access the subscribed areas of interest for a specific buyer and filter the content of interest enabling the buyer to see a filtered view of items in the various nopcommerce stores/categories of items.
I do have every intent to procure premium support but would like to ensure that I do not waste anyone's time and do a proper spec.
Would really appreciate some guidelines and/or documentation/white papers to get me started.
kind regards
Zack

I think all what you want is available out of the box. For (a) and (b) check documentation and forum topics discussing multi-store features and configuration. For (c) check ACL on  products and categories and filter features and plugins

Thank you Eduardo,
This is helping a lot.
On the configuration side, just to ensure that I start correctly and not try and salvage later.
My objective for the multiple stores is as follows:
1. There will be X number of different vendors/customers with different branches. As an example think of Walmart that has many different branches and not all products is present at all branches.
2. The a second vendor, similar to Walmart in different towns with different branches.
I want to be able to have a different theme and catalog for each branch of Walmart and vendor 2.
A typical customer must then ultimately be able to visit a specific vendor and drill down to a specific branch.
Other search example where a customer can search for specific product and must then render the product and any vendor and all branches. Customer can then decide where to buy.
Thanks

I think you can do it probably out of the box. What I understand from you explanation by "vendor" you really mean a "company", and not like the concept in Nop of a vendor (check multi-vendor/ drop-shipping feature in Nop)  like Walmart and Kmart each with different products en each of their branches.Am I right?
If each one company will have its own general product catalog its own branches (not always with the whole general catalog)which can be accessed by the same customer base the case can be handled by a multi-store and multi-warehouse if you want to control inventory from the Nop application. If both (or more) companies will share the same general product catalog and customer base then they can altogether be built on a sole multi-store. Otherwise it would be better that each company and its branches is built on a separate multi-store. Each individual store within a multi-store can have its own skin design.

How many companies and branches are you talking about?

Hi,
Quite a number actually.
The intent is to list a number of companies and their products.
The companies and their products must be accesable individually by a customer or by product search displaying similar product at all companies(stores)
The mentioned customer(s) will in turn be managed by a different app. From this app I will be passing search criteria (parameters) to nopcommerce. Based on the parameters I then want to display the products and let the customer perform the purchase.
To enable this approach I want to make sure that I setup and build the nopcommerce store(s) correctly for the end goal in mind.
Ultimately, after the transaction I will need to get some results of the transaction back to the custom app for further processing.
i'll get this from the database so thats the easy part.
Thanks!