I think it is interesting that you think T foils will help solve your nose diving problems. Don't you think you could get just as much benefit from redesigning you spinnaker? from my experience getting a spinnaker that creates more lift works very well and it's what i have done on my Taipan I also did this on my F18.Most kites are just cut down Tornado or F18 designs so you need to tell you sail maker what you want not just get what they say is everyone else has got.

Danny