As for radios, as Woodsy said, you NEED a 4 channel radio. 6 channels are nice to have, but it's not a requirement, nor is a computer radio. If your budget allows for a sophisticated radio, by all means get one, but don't think that a fancy radio is required piece of equipment.

As far as brands go, check with your local club. They will tell you who can train you, and you will need to have a brand compatible with their buddy box.