If you have been using foils, why don't you go to the newest better foils which have depower and give you more range than some inflatables. You have been using f-one foils which don't have the biggest range, and the 9.0 is a really slow kite compared to others. It has a small range, and doesn't turn too well. These kites might be part of the reason why you have had trouble going upwind. I would reccomend you go to a http://www.flysurfer.de
mastair 12.0. This kite is very powerful, yet still fast, and you can go huge in 15 knots. It has depower which helps you go upwind, and with your weight, you could probably take it up to 20 knots. I am completely sure it is faster than your 9.0 and much more agile and powerful, I have the mastair 12.0 and sell flysurfer.de in Mexico, I have also flown the 7.0 and the 9.0 many times(a friend has them). I forgot to mention, relaunching the mastair is so easy, just let go of the bar, and it gets on the trailing edge by itself, then just hook in, depower and up she goes. It also has less bridle lines, so they never tangle(mine haven't). Regarding the board, try to move your straps as far forward as possible on the board so that you have a more centered stance. This will help you with planing in the lulls, and in going upwind easier, and planing earlier. You should also look at the italian http://www.loose.it
boards, the AX160, or the twintips would be great for you. I think the usa dealer for flysurfer.de is in New Jersey, this is their site: http://www.flysurferusa.com
They also sell the loose boards in the U.S.
Another advantage, these kites are cheaper than blimps.
I know this may sound commercial, but I am genuinely stoked about these kites, and this is my honest opinion.(I also sell takoon in mexico)
Let me know if you get the mastair, so that I can give you some tips.