allegro,
You didn't say whether you want a 1948-50 early or 50 late bed. If your after a repro bed there are a lot of companies that reproduce whole beds or bed parts. Dennis-Carpenter.com, BobDrake.com are two right off the top of my head. Pick up a copy of Hemmings motor news and peruse the classifieds.
The early ford v8 club is also a good source for parts. earlyfordv8.org
I just noticed your in Texas, you should be tripping over them down there!!!
Good luck...
Jeff