I used a few Lego pieces for my workbench - not all, but a few work.
GW - there's a toolbox on the Sector Mechanicus servitor/crane set; the mekboy workshop has a few spare tools; several IG sprues have some extras here and there; the recent promethium tanks also have spanners, tools, and hoses/welders. A lot to pickup individually, but fleabay has some sales. I was able to accumulate a decent workshop worth of tools.
Might also look at some O scale railroad kits.