I did a number of hand blown glass lamps a few years back that I built a giant mold for- 2 part machined out monster with lift off hinges. Used a local glass blower here in Los Angeles named Josh Gilfand from Revolution Glass http://www.revolutionglass.com/custom/page_custom.php.
He was great to work with. In hindsight though, the mold was probably a waste of time. He had enough control that I could have built some masonite templates that we could have worked off of.
I would guess, unless you have a monster budget, find a local blower. OR, find someone that that works at a larger company and see if he does side work after hours.
Hope that helps.