Motorcycle Repair: Slip-ons or hole in baffles, sportster 1200 custom, stock pipes

Question
Hi, I have a 2007 Sportster 1200 Custom and I want to change my stock pipes to obtain a louder sound.  Someone suggested Rush slip-ons instead of Screaming Eagles because of pipes changing colors (don't know how true this is).  Nevertheless, I don't know which slip ons to choose, 1.75, 2, or 2.25.  What's the difference?  Also, will I have to get something remapped?  Another question, another gentleman who owns a repair shop said that if all I want to do is obtain a louder sound that he could just put a hole in the baffle.  If that a good thing to do?  Will my bike continue to pass inspection?  What problems will this cause, if any, to my Harley?  Thanking you in advance for your assistance.

Answer
First, pipes change colors due to heat. The leaner a bike runs the hotter it runs. When you open up the exhaust by changing pipes you are leaning out the bike. The sizes of the pipes you are talking about is the diameter of the pipe, so you have to get mufflers that fit your pipes. Once you have installed the mufflers, if it were me, I would get it remapped. You are leaning out the bike and remapping it will bring it back to where it should be. As to pumching holes in the baffles, I dont recommend it. First, you dont know how many holes to punch and second, you will actually lose some performance.
Good luck and happy riding
Mike