The classic Kodak "bullet" safelights are a dime a dozen on ebay and there are 5.5" round filters for just about any purpose. Use the amber OC filter for most b/w enlarging papers; the red 1A for ortho litho films; and the dark green #3 (sparingly) for handling slow panchromatic materials. The filters swap out in seconds and they take a standard inexpensive 15w bulb. Maybe too small for a commercial darkroom but perfect for home darkrooms.