Here is a pic of what I am talking about. They don't really mention it for powdered lime, but it will work if the lime is dry (bagged). I used to work at a housing development and the homeowners board bought all the supplies for reseeding the common grounds. Needless to say they went with the cheapest bid and bought powdered lime. You should have seen the swimming pool and tennis courts when we were done.
If you are seriously wanting 1 ton per acre, the easy way out will be to hire a spreader truck. Takes him 1/2 hr and you hand the driver a check. The only large drop spreaders I have ever seen are like 1950's or older. I'd hate to shovel 5+ tons of lime. If you have some small areas a spreader truck can't go, you can always buy some bags of pellet lime for those.