I, too, used the famous Build Your Own Darkroom book to construct my sink. I used fir and ply throughout and finished it with waterproof paint. Much cheaper than metal, and your saw determines all dimensions.
Mine is 41" high at the front rail and is 7" deep at the drain end. I'm 6'1" and this is just the right height for me. No fatigue, back ache or "jimmy leg"