Tim McCreight has plans for two simple benches in the back of _TheComplete Metalslmith_. My husband was able to build me a quiteservicable bench by using those plans. It's not pretty, but it'sfunctional.
10.47$ @ Amzon.com
Check out Tim McCreight's, 'The Complete Metalsmith'.
There are 4 pages (166 thru 169 in my edition) with instructions,pictures & material list for a jewelers bench.
Tim McCreight's book The Complete Metalsmith has plans for a bench.
you might check the July and August issues of Lapidary journal forbench plans. They offered a 2 part article about making a portable(but sturdy) bench including a materials list, detailed instructionsand photos.