So you will need to build something that when the leaver is up... It pushes one switch and when the lever is down it pushes the second switch and releases the first.
current contact rating.. is how many amps the switch can handle before it shorts out internally. For low voltage stuff like out interface boards get any switch that can handle at least 1/4 .25 of an amp. If your going to drive motor's etc with a switch you would need to find out how many amps the motor draws and make sure you get a switch that has a rating higher then what the motor draws.
Switch function.. This is easy. Is it open all the time (normally open) and when you active the switch is closes. Is it (normally closed) so when you activate it it opens or function can be labled as (ON-OFF-ON) This is a 3 position switch when the switch is in the middle position it is off when it is one position one contact closes and when it is on the other position the other contact closes.
Termination style This is basically why kind of terminals are on it that you will attach your wires too. Like screws, solder points ect. Basically when you order parts they show you a data sheet, look at it and usually they describe how the switch looks, from that picture you can see how you will connect to it.
Actuator This is how the switch is made inside. For instance plastic actuator would be a cheap switch, wouldn't last long, where a ball bearing, or brass actuator would be more heavy duty.
Contact form is usually the material that the contacts are made out of internally, ie (Gold, Brass, etc) The better the material the more expensive, really for what we are doing, buy a product that is not the cheapest, but not the most expensive.
Radar, when your ready to place an order, drop me an email, I would be more then happy to discuss it with you to make sure your getting the right parts. It is always nerve racking when you order something you can't see in your hands first.
Or you can alternatively post the part numbers here and I can check them. and describe the part you ordered to you in English :)
Trev