Management of entities with many to many relationships

[heavy]

I'm finding myself with the need to have a tool that lets me manage multiple inter-related entities.  It's probably best described through an example.

I have some products.
I have some customers.

Certain products are bought by certain customers, and certain customers buy certain products.  I want to be able to build a relationship map between my customers and products, and even between customers themselves.  Maybe the differentiation between customers and products isn't even noteworthy, they are all just distinct entities.

To make that clearer, consider this:
- product A is available to customers X, Y, and Z
- customer Y can purchase products A, C, and D
- customer V is related to customer Y

So the way I want this to work is:
1. I click on product A and I'm shown all the customers that the product is available to.
2. I also want to see a hierarchy of customers if one exists.  So even though customer V is not related to product A, it is related to customer Y (which is related to product A) and therefore I should see customer V as a child of customer Y on the product A page
3. Have a notes/comments section for each product or customer page.
4. Relationships can be ordered, so product A could always show its customers in a specific order.
5. Each entity on the page is a clickable link to its own page where it shows its relationships.

Hopefully that makes a little bit of sense.

Questions:
1. Is there anything already out there that can do this sort of thing?
2. Anything in CMSMS to make building this easier?
3. How would you design something like this?

[heavy]

I've started working on this, so if anyone else would find this useful and has suggestions on what they'd like to see in here, let me know.

[trick]

CMS Made Simple is a CMS, not an e-comerce solution. If you want one of those look at zen cart: www.zen-cart.com.

[Ted]

This isn't e-commerce specific.  It's just an example.  He just needs a module that shows those relationships, almost like a directory.

And TBH, if someone integrated an e-commerce module into CMSMS, I wouldn't turn it down. 

[heavy]

I've just released the first version of this module, details are in this post: http://forum.cmsmadesimple.org/index.ph ... 670.0.html.