I'm going to guess used, and you might do well to err on the longer end when you buy one and be ready to have a shop extend the threads, otherwise it'll be a PITA to get the right length.

e: looks like you're already falling forward to get to those bars, you sure you want the front lower? Alterations like this have a snowball effect, if you're not careful you could need a new... everything on the front end- stem, bars, fork, wheel, tire and tube. If you're going to do all that, maybe threadless is the way to go. A lot more forks out there are threadless and stems adapt easily with a shim, headsets can be less than $20.