Hey Buzz...
Buying and commenting on whether to buy a seat or waste harness is a very individual and preferenced comment. I had two lessons on a girls waist harness and found it very comfortable. After these lessons, I however bought a seat harness as I could hold more power as a beginner, and found it more comfortable as it eliminated the 'upward pull' and also the force on my ribs. My harness is a Dakine Hawaii Fusion 'S' and for me, it's perfectly. I recently used my boyfriends harness for about an hour so his younger bro could wear mine for a lesson. It gives a completely different pull as you're centre of gravity has been altered, and this also makes you're stance slightly different, and a little while to get used to. This harness was a near-perefect fit, however, witht eh force of the kite it did pull up and the pressure on my ribs was painful. Before you buy a waist harness, ask a mate if you can use his harness for 30minutes, because if you don't like the pull, or the comfort factor, you may have saved yourself the money.
All the best with your search