China says it is to sanction US firms involved in Taiwan arms sales
Adds that US government is in 'total disregard' of China over the matter
General Dynamics is the first name that comes to mind as I recall that their tanks are the ones involved here. I'm not too sure which other firms are involved here but it is probably just a handful only.
The sentiment over the matter is what is more important, and this certainly doesn't help to give you the impression that relations between both countries are that cordial as they look to resolve trade tensions as well.
Update: Other related companies believed to be involved in the sales are Raytheon Co and Lockeed Martin Corp - providing Javelin missiles.