I don't know if this has been posted already by anyone else...
I created a stealth bomber with infinite range and have tested it. It can be intercepted also. Here are the settings for anyone who is interested...
Class: Air
Unit Abilities: Immobile, Infinite Bombard Range, Stealth
Special Actions: Bombard
Unit Statistics: Bombard Range = 0
Air Missions: Bombing = OFF
Operation Range can be set from 1-8 and this controls recon and precision strike (sorry, no infinite precision strike)
I also turned off the load option (Stealth Bombers/Fighters on Carriers

)
It also appears that the AI will only use them in an eight tile maximum area. And will not infinte bombard. These settings can be set for the stealth fighter also...