Your best bet is to go for a seat harness to start off with and progress onto a waist one when you are a more experienced rider.
Seat harnesses have a lower hook position so they give you the advantage over the kite when overpowered meaning you can handle more power. The disadvantage is one of comfort.
Waist harnesses give total freedom of leg movement, Great! On the down side the hook is higher so the kite has the advantage over you when overpowered, this can result in bad form and less ability to handle power. In addition to this a waist will ride upto your chest if your technique is dodgy making the situation worse.
The Mystic and the new Scrub seats are well worth a look.