The Go-To guys for (seriously) custom fabrication and general mechanical work is E-Mortal Customs here in Calgary. People come from all over Western Canada and the U.S. to get work done by Rick and his team; they bleed Jeep.
Another shop here in Calgary that gets accolades from the off road community is Broken Axle. Dave and his guys definitely know their stuff...even though Eric insists on driving a Jeep with square headlights.
There is a national chain off road shop here in Calgary as well...I'll just leave it at that.