Hmmm... interesting idea. I know you are building it slim for obvious reasons but I believe an efficient vacuum table requires a larger volume chamber for static pressure. I wonder if it would benefit you to create a couple down tubes which hook to a larger chamber. I'm thinking on a larger scale though... I have a 1200cfm cyclone collection system I use.
Please let me know how your system works out. I'd be interested in the slim design if it has good holding power.