If you look in the yellow pages for a lumber yard (not a HD or Lowe's, but something locally owned who deals with contractors) you can probably find someone who works there who will do it for you on his/her own time. Most people who work in those types of places have employees who have this type of skill and/or equipment and would be glad to do it for a reasonable price.
The wooden letters used at the chapter houses at University of Arkansas are about 5 or 6 feet tall.
Threaded Mode
