Check out the Witzl's latest offering in the parts for sale section (I think). The 1.5w UHF would be perfect for what you need, and provide good coverage (I wouldn't expect the full 8km range) but would be more than adequate in the city.
I've got a pair of the 0.5w ones, and whilst they are good, I would love to upgrade to the 1.5w because occasionally they just don't reach far enough for my liking.