Fife - 88 underfoot isn't a huge handicap, but your instructor is correct. Width is not so much about your height, but you tib / fib length. Look up work by Dr. John Seifert. He's at Montana State University, but on sabbatical now in Austria. He has a great prezo on YouTube from PSIA National Academy, if you really want to geek out.
I have a number of private students in your same boat. A screaming deal right now is the Dynastar Speed Zone 10. I taught on it for a season or two. Great ski. Very comfortable all day, five days a week. I can model technique at 3mph in the beginner area, or at 30mph on advanced terrain. Last I checked they were $350 / w binding on close-out. There is also the Speed Zone 12 and 14. That might be too much ski for you. I enjoy them, but not to work on.
If you want o go all out, if this is your passion, if this is the craft that you want to hone, Stockli Laser AX.
Enjoy.