I am going to assume that you are only using dual line power kites right now. Quad line (4 line) kites will allow you greater control and the ability
to stall the kite or shoot the kite to the edge of the window for more or less power. That may be just what you need at this point....but even a quad
line kite will be difficult to master in the wrong winds.
If the winds are just to strong for the size of kite you are using, you have to drop down to a smaller size kite. Doesn't matter if its dual line or
quad line. I would suggest that while looking for a quad line kite, look for one that is sized differently than the kites you currently have. Not
only will you get greater control from the quad line kite but with a different size you will be able to buggy more often because of the increased wind
range. When the winds are a little light you can pull out your larger dual line kite, when the winds get a little bit too strong for that one you can
then pull out your new quad line kite. Best setup is to have a kite for all conditions.
I am pretty sure that you will eventually trade out all of your dual line kites for quad line as they are much more convienent to use.