The hammer on a double action revolver isn't for decoration only, that is if the hammer is exposed. It is so you can fire the revolver in single action mode if desired. If the hammer isn't exposed or is bobbed then that revolver is DA only. So in either case the hammer is never a decoration. The style of the hammer may be more decorative on some models than on others, but that is a different matter.
There are revolvers on the current market that are either SA or DA or both, just like semiautos. Only the SA models have to have the hammer cocked manually to fire.
So if your concern is the added safety factor of having to manually cock the hammer before firing, then a modern SA revolver is for you. However, the DA/SA revolvers have a built in safety factor of a sort also, their triggers always require considerably more effort to pull in DA than in SA. How much more depends on the model and any smithing work that has been done to it, but it is always more.
Oh, and Welcome to TFL!