Just an FYI, Powdercoating will not hold up on exhaust pipes. Weather it be for a car / motorcycle / etc..
The heat is too much for the finish, and will break down and start to chip,crack,look like crap.
Ceramic Coating is the best way to get a durable finish on high heat surfaces, such as exhaust pipes.
Local shop here in Chicago (LO-KO) will do a set of pipes for around $100, in either polished silver or flat black..