wil,
I doubt the rubber hose will cause that much of a difference in height. The most probable difference is that there is less metal to metal noise. This is what I'm getting in my car. I have rubber hoses for my front but none for the back. Once in a while, can hear loud clunking sounds because apparently, when taking corners and such, the springs will rotate ( !?!?!?! ) and when it comes back to it's original position, there'll be that clunking noise. Unsure about this though.
As for the type of rubber hose, I ain't too sure what kind of hose would be suitable but I'm just using a normal hose that fits the springs nicely. Not lose, not tight.