Nice setup on the vacuum. Note, however that the pump will not hold the vacuum on it's own if you turn it off - it will bleed back through the vanes and discharge your reservoir.. a check valve at the discharge of the pump, or better yet, a electric 3-way mac valve will seal off the vacuum pump when it's off. By nature, the check valve with it's ball and spring will cause a slight reduction in the ultimate vacuum you can pull (which I didn't like when I used one) - so I now use an electronic three-way mac valve to disconnect the pump from the system coupled through the same relay I used to cycle the pump on and off...which then leads to another issue where you need some additional electronics to make everything work together....
A vacuum controller switch coupled with a relay will automatically turn your pump and the valve on and off at a set vacuum level...I've even got one wired into a small PLC controller so I can control all the timing of the valve, pump, switching on and off, and I even programmed in a timer controlled by a series of switches (in a binary fashion) so I can set the controller to not turn the pump on after 1 to 9 hours (so I can go to bed or leave town and rest assured that it won't stay on indefinitely). The next step is to connect a modem to the PLC so it will call me if my pump stays on for more than 15 minutes (indicating a leak occured in the bag)...just kidding on that last part although it IS possible!
If you put a small reservoir between the pump and the mac valve, the pump will also have the opportunity to start from ambient pressure instead of being hit with vacuum immediately.
Lots of plans and all the pieces parts needed can be found here:http://www.veneersupplies.com/default.php?cPath=60_36
One last thing...I had my vacuum switch powering my relay with AC power initially but I had a lot of trouble with bouncing of the switch (making the pump turn on and off very rapidly for a second before it reached steady state). I would recommend using a 12VDC relay (instead of 120VAC) and a wall mounted power supply for the vacuum switch and relay. The relay then can switch the 110VAC to the pump and the valve. Apparently the amount of AC current needed to switch the relay creates magnetic currents that disrupt the sensitive vacuum switch.
I know this is complicated, but compared to the alternative of leaving the pump on full time, it is amazing once it is all together.
Then again, these pumps are designed to be left on for extended periods...so it's not a big deal if you leave the sucker on for hours (although mine does tend to overheat).