mark if u don't want performance look just use the stock pipe, either the 50v or av10 stock pipe and remove the rear baffle like shays artical said to if u run the av10 pipe.
seriously if u don't go for a real pipe cuz of the look, then don't even try and get any pipe at all use ur stock one you obviously don't want the power, and paying for a pipe thats does little or nothing and makes the bike louder and shittyer looking is stupid, the stock 50v pipe is quiet, gives good power, and looks the best.
i've gone neck and neck with a bike that had the same setup as mine along time ago with the high priced leovinci pipe (not the cobra) and my bike was faster all around with the ninja.