Copper is fine, but keep in mind there are two types you can buy. M and L, and I think M is the stronger of the two metals.
For the past 3 weeks I have been getting involved with some stuff called Naval Brass at work. It was for a handrail, and while the handrail was quite simple in design, tig welding it was another story altogether. Man that stuff is made of 4% copper so you cannot braze it, cannot stick weld it, cannot wire feed it, only tig weld it and even then its not very easy.
Of course this handrail was right on the water so the constant wind blew the gas away and December is not the best time to be outside in Maine. Still we managed to get the handrail done. It looks good now though and it should. The material itself cost 9 thousand dollars for 50 feet of hand rail.
I doubt this will be any good to anyone, but we have several feet of the stuff left over. Its one inch, and one and a quarter inches in diameter and schedule 40 in thickness.