Trucks have gotten taller because of beefier frames, taller engine packaging, and taller cab requirements to keep people happy. The tire spaces are also a bit bigger because most trucks already come with 33" or 34" tires from the factory (275/70R18's or 275/65R20's respectively). You need those bigger tires to meet those bigger payload numbers they love to market.
And as for lowering, generally speaking an inch won't do much harm, especially since you have a solid front axle on your Ram. Only things you will most likely need is an adjustable track bar, someone to fab shorter springs, and possibly a shock with a shorter stroke length to match (maybe, but I don't think it's needed for an inch). Are you sure your truck is an inch too tall? I have a pretty low garage and can get my truck in my home. The only thing that hits is the antennae. My problem is that my garage is just too shallow.