Finally! I searched the half the world (ok, maybe a little less) and finally found a affordable valve unit with 1/4" NPT threads that fits snugly on the vacuum press project.
This valve is used on the main reservoir that goes to the vacuum line. By adding this valve, you can "pre-charge" your system with vacuum pressure so you get a slightly faster initial pull down in the vacuum bag. The valve can also be added to the lock-on vacuum connector so the vacuum pressure can be turned on or off right at the vacuum bag.
I was in Lowes not long ago and they has this same item on sale for $9.95.
Buy here and save!