i bought a hafco vac 55 gallon dual venturi vacuum head and made a custom silo with a tapered bottom and a ball valve with fork lift slides on the bottom and park in my booth vacuum up my media and when blasting i park it over my blast pot and open the valve and let it gravity feed down through a surface tek funnel through a perforated steel peice of sheet metal for a screen to remove all the foreign debris...works well...i do go through floor tools...like the tube on the top half...it wears out due to the amount of abrasive traveling through it.i will post pictures as i am on my way out of town for a few days.total investment around $3300...
i had the dual venturi option added tal to john rodriguez if you call super helpful and hooks you up with demo models if available
http://www.hafcovac.com/store/index....cuum-head-only