To be honest you have to think logic, You will need 4 camera operators probity 1 vision mixer operator and you would want a assitant incase any thing went wrong. That’s 6 friends which really unless its a hobby you would need to pay. I wouldn't suggest buying a vision mixer. Just hire one for the day. Panasonic and Sony are the best mixer manufactures. Then on the other hand you have three other people and your self so if the conference people are paying they will prefer this option. To be honest once your cameras are in sync it should take about 2/3 days, it took me about 2 days to edit together 2 hours with three cameras. The only reason I would think vision mixer would be better is if you don’t already have the correct software. But then you could download adobe premier pro 2.