I am looking for a system that will allow route salesperson to use a laptop to

1) Add and Update customer information (name, address, phone, invoices, etc.)
2) Contain product information (product number, description, 3 levels of pricing, package quantity).
3) Track their truck and warehouse inventory.
4) Create price quotes and invoices.

I would like to deploy the same system on a web site so

1) The central office can maintain the product information.
2) The salesperson could synchronize with the web site by sending updated customer and invoicing information to the web and receive updated product information from the web.
3) Track the company’s entire inventory for their central warehouse, and each of the salesperson.
4) Would also like to be able to create an e-commerce site utilizing the product and inventory information.

I would prefer free. If I can’t find that I would like to be able to try before I buy.

Look into OSCommerce. I don't know if it has all the features you need, but most of them. It's also easy to add new modules to it if you need that (there are many to download, too).