Question: I am searching for a streaming solution, my company need to record and stream a live event on a Website, I am looking for hint as to which technology we should use, and what do we need in our setup.

This is how I see that for now :

We will need to install 3 camera, 1 console (to manage which camera is streamed), 1 Streaming server, on the location of the events. And our website would have a plugin (Flash?) showing what is streaming by the Server at the event location.

Do I have that right?

Any of you have any experience with similar technology?

Answer: 
Try modelling your sales as a transaction - with a "header", i.e. who sold to, when sold, invoice # (if applicable), etc. and "line items", i.e. 20 \* product\_x @ $5 = $100. The safest approach is to avoid relying upon prices etc. from the products table - as these will presumably change over time, and instead copy much of the product information (if not all) into your line item - so even when prices, item descriptions etc. change, the transaction information remains as was at the time the transaction was made.
I think you need a table with fields showing the transaction properties per customer
OR
a table with fields - date, product(foreign), quantity - this way you'll have no problem with new products