Well welders have been using these for years but it only includes a funnel and no hood so it is only good for relatively small torches and very localised ventilation.
www.ventafume.com
I used one in my garage for a while and it worked well. Based on your description, in my opinion, you should have a full overhead hood. There is no off the shelf system that I know of. I suggest you do the research on fans, sheet metal hood design, and ducting, as well as the fundamentals of ventilation and find a local contractor to build it. Working with enamels should not be taken lightly. Is there no one else that could help?