More information needed. Are you using a handheld or base/mobile? Can you put something up in an attic, where the additional height would be helpful? How much height do you have available? What frequency range(s) are you interested in? What is the construction of your building? Can you put something near an outside wall or window? I understand many like that RS discone (looks a little like a spider's web), and given its construction, it probably is better off indoors.
73 Mike