This should work for you. I have attached a sample of what I worked up. The top left table is your list of Vendors. It's easiest if you keep them to one word, but the link shows a work around.
To the right are the lists of tools from each vendor. Below that is the data validation. There's a drop down for Vendor. Once a vendor is specified, the dropdown for that vendor's tools is enabled.
See if that will get you started and let me know if you need further help.