Roof truss for lean to on side of building

I am looking to construct a lean to on the side of my building that is approximately 25' long by 16' wide with half scissor trusses to span the 16' distance. The roofing would be steel. I am looking for someone to design the truss to ensure they are strong enough for required snow load. Live in Duncan, British Columbia. I would like to construct the trusses from 1" square steel or another basic readily available steel. I would like to know an approximate cost for this.