Do you have reef points in your main? We find that a 110% jib will work fine to over 30 knots, at which point you can reef the main and sail in over 45+ knots of wind. For a true storm jib, you would likely want something in the 50% or smaller range. I think any good sailmaker can advise you on the proper sail. We here, of course, recommend Hogin Sails [http://www.sfsailing.com/hoginsails/]

The (maximum) dimensions for the 110% class jib are:

Luff: 28' 6"
Foot: 10' 4"
Leach: 25' 0"