A good deep vacuum pump?
I'm looking for a vacuum pump for use with projects like the fusor included in make magazine, a laser tube, or a plasma ball. It doesn't need to move huge amounts of air, but nothing below 1.5 lpm. It also needs to have an ultimate vacuum of at most 25 microns. I have been unable to locate any pumps which meet these standards, all of them have ultimate vacuums of around 100 to 75 microns or are completely unlisted. Do any of you have some experience with these and some advice. I don't need something for pumping out heating/cooling units daily, just a very deep vacuum a couple times a month.