Here in the US, CB radios operate below the amateur 10m band. It sounds like in SA, their CB band is just above the 10m amateur band. Otherwise, they are basically the same. This is what most recreational wheelers in the US use because they are cheap and no license is needed.
In North America, FRS (family radio service) is in the UHF spectrum (roughly 450MHz) and coexists with GMRS (general purpose mobile radio service). FRS is limited in power to something like 300 milliwats, while GMRS can go to 50 watts or so (I think). FRS is like CB - no license required. GMRS requires a license, although many use it without and it doesn't seem as though the FCC enforces it much, if at all. There is also a CB-like band in the 150MHz VHF range called MURS, which allows a couple watts. It isn't well knows, so few people use it. Anyway, I am guessing your VHF/UHF allocations in your country are similar.
Since your CB is similar to ours, and your VHF/UHF services are probably similar to our FRS/GMRS and MURS, I can make a few observations: CB's are cheap, but have poor local propagation since most of the power is radiated as a sky wave rather than a ground wave (I won't go into a lecture on RF propagation vs frequency - just take my word on it
). During favorable solar activity you can be deaf to someone transmitting 10 miles away, but hear skip from someone 500 miles away. This is why HF (frequencies below 50MHz or so) are used for long range terrestrial communication - they don't waste power transmitting a strong ground wave, and the low frequencies allow the sky wave to reflect off the ionosphere and the earths surface. It is possible under the right conditions to transmit a tone burst and receive it several milliseconds later after it has travelled around the earth. However, these same qualities make it less than optimal for local (i.e. less than 50 miles) communications. Sound quality is variable, and can easily end up sounding like two soup cans connected by a piece of string.In addition, due to limited bandwidth, transmissions are generally AM, which is more susceptible to noise and interference. Also, antenna length is inversely proportional to frequency (proportional to wavelength), so a longer antenna is needed.
VHF and UHF are more line-of-sight. VHF can propagate somewhat beyond the horizon, while the 450MHz spectrum is more strictly line-of-sight. These radios are typically FM rather than AM, and audio quality is typically superior to modern digital cell phones. Since the power is radiated more perpendicular to the antenna (parallel to the ground for a typical vertical antenna), the radiated power is sent to your nearby friends rather than uselessly toward the sky. You also avoid interference from people skipping in from hundreds of miles away. Antennas are shorter, or for a similar length antenna you get much higher efficiency. These radios are usually built on commercial platforms, so they have high quality circuitry with excellent performance. Pretty much, if you can convince everyone to go this route you will enjoy your comms so much more.
Amateur radio is basically the same world-wide as far as frequency allocations go, at least in the HF spectrum. Licensing is up to the regulatory body in your country. Amateur radios obey the same physics as any other radio, so for trail comms a VHF or UHF FM rig is the best bet. Unfortunately, this requires everyone to have an amateur license, and the equipment is more expensive than the cheap CB radios. IMO, whether amateur VHF/UHF or commercial VHF/UHF, it's worth it compared to HF CB if you can get everyone on board. Better fidelity and better range.