Kite You will want atleast 2 different kite sizes although most riders gave 3 to cover all your wind ranges from 10 knots all the way up to 45 knots. This depends on your weight and location where you mostly kite to which sizes you will choose. Generally speaking a 6 meter, 9 meter and 12 meter is a good combination of sizes. There are many brands and different kite models for different type is riding, beginners, freestyle, wave riding etc.. Bar The kite brand and model you choose will come with the bar and lines.
Board Again this depends on the type of riding you will like to do. Big boards 150 cm plus are best for beginners. There are dual directional/twin tip boards that come with straps or wake style boots, kite surf style boards, strapless boards and hydro foil boards to name a few.
Harness There are two types of harnesses, seated and waist. It is usually best and most comfortable to learn with a seated harness and theb progress to a waist harness if you choose to do so.
Safety Systems Todays safety systems are much advanced than only a few years ago. This is the release mechanism that is part of the bar. Your bar will also come with a safety leash.