Scott,
I don't know if this is feasible or what it would cost, but could you possibly move any of your inlets? I know it requires some work and might not be possible, but wouldn't it make more sense in the long run? Then you can utilize all the benefits of the system you already have and not need to supplement your system with another portable vacuum? Maybe even adding an inlet rather than moving one would help, again only if that's a possibility.
~Steven