These device's can be a blessing or a curse, but because of there ease of use and design they are becoming easily available and a "Must Have" item in the workshop. Several companies sell complete systems ready to go, other's specialize in just the vacuum systems required to run the system. The information which follows is from my own personal experience in setting up a system and does not necessarily apply to all systems.
Essentially there are two ways of supplying a vacuum to your chuck. One is the a electrical motor vacuum pump, and the other the vacuum is supplied buy using compressed air through a Ventura system. The advantages and disadvantages are listed below. To install a vacuum chuck on your lathe it must have a bored headstock spindle with no cross holes bored through. There is a system made by Packard Woodworks which circumvents this problem.
Single unit supplying vacuum source.
Size.
Operation.
Quiet.
Price of unit.
Yet another plug used.
Maintenance.
Belt drive.
With a little searching of car scrap yards a suitable vacuum pump (York), can be purchased for around $35, and then all that is required is a ¼ - ½hp electric motor. Bolt both on a single piece of plywood with the addition a belt and you are ready to go. Motor or pump should be mounted so that the belt is free running and not too tight or the belt will wear prematurely.
No moving parts
Easy connection
No maintenance
Compressor required.
Noise
Air Movement
Unless you already have a compressor installed you will have to purchase one which can raise the cost of installation by as much $300 depending on the compressor chosen. However this can be a blessing if you purchase air tools at the same time. Which can assist your in the workshop by everything from carving to sanding, and drilling. Do not buy a gas powered compressor for this use as is well understood the fumes will have a strange effect on your turning as well as the turner. The noise from the compressor can be combated by enclosing in a loose fitting lined with egg trays, and louvers face down or doubled, for ventilation. Air movement can be controlled by directing to the outside of the working area.
The main purpose of a vacuum chuck is to hold an object on the lathe without marking the surface. So with this in mind you can design your chuck to suit your needs. Of course you can always purchase ready made chucks but unless you intend to turn the same shape and size of vessel every time you will eventually be forced to make your own.
Materials
Chucks can be made from almost anything which will not buckle under vacuum pressure, and is not porous enough to allow the air to enter enough to lose the vacuum. Aluminum, steel, wood, PVC piping, all can be utilized in the making of your chucks.