Don't get a quick release harness...If you do, you will regret it when it dumps you in a nice breeze and you mess up a race. A good knife is just as effective, if not more so than a quick-release. Go for a Spinnaker Shop harness. It is nappy style, it's wicked comfortable, and is probably the best standard harness out there besides the Grand Banks.
Well, you can either get a really crappy one that you will regret getting due to how many straps there are, and end up chucking it and getting a new one, or just spend the money for a good one and use it for as long as you fit into it.