PLSN/FOH has put their annual "Event Production Directory" on-line at http://www.epdweb.com/ It's not exactly a perfect or complete list (the largest theater dealer within 800 miles of me isn't listed) but it's got a lot of good information.
I would suggest letting all of your favorite vendors know if they are not listed there they should take the time to go there and list themsleves.. We are going to promote this site heavily on all of media outlets so I am sure they will reap benefits by being listed.
Welcome to the booth. Go introduce yourself in the new member forum. Do you work for PLSN/FOH? The new memeber forum is your one chance to shamelessly promote yourself without getting hassled.