Patience, aren't you borderline petite? Or am I wrong?
What size are your feet? Those variables are important IMO. If you're on the shorter side, high-high heels can look a little weird nad stilt-like. Even Stacey London, who generally tends to push the highest heel possible, acknowledges this.
Also, smaller feet = smaller heels. A size 10 foot can wear a 3" heel with greater ease because the angle is less dramatic. On a size 6 foot, 3" is 1/3 of the entire foot length, which pushes it at an awkward angle. You'll get the same look as a size 10 foot in a 3" heel with a 2" heel when your foot is smaller. I don't know if that makes sense.
As for leg lengthening, I know you mentioned in your other post that your inseam is 29". At 5'3 or 5'4, that seems like a pretty average length, so adding just an inch or two is still going to give you enough length.
Shiny, have you tried a chunkier heel with your skinnies?