Have you thought of pasteurisation? I've never tried yet, but I've watched how to do it and looks like it's a simple and efficient method to stop the carbonation at the level you want to maintain it.
Great article. Ive been brewing for about the same amount of time as you, and it is fun to see how others have gone through a very similar process. Thanks for the BJCP info, actually I hadnt paid much attention to all that, and I have already downloaded interesting guidelines and information...