A hood is better than a funnel - just my opinion.
With a funnel system the fumes have to be pulled in. With inline fans the amount of suction drops off dramatically as you move away from the mouth of the funnel - and what about the heat and fumes from the torch flame - they go up, not forward? Creating enough suction to keep all of that out of your face with a bravo running with both stages probably requires enough CFM that the flame would be disturbed by the air movement.
After much trial and error my conclusion is that a hood that extends out over your torch and head is better. I also have an attic/greehouse type fan in the wall in front of the torch that is variable speed for fuming.
If you'll be working with long tubing for vessels or goblets (especially if you need to use grabbers) a straight bench is going to be better and you may want to put the torch on a sliding base so that you can tip the tubing below the bench on either side (you can see that type of setup in Tim Drier's Corning demos). With a corner setup long blow tubes or punties will hit the table.
I ran one OGSI 15 on an Alpha and it wasn't enough, so probably looking at 2 or 3 cons for the Bravo, at least
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