Any Screamin Eagle slip-ons that fit 2005 models will fit your bike. I think the range was 1999-2005 but I am not sure. I bought a set off a 2004 dyna. Got them cheap. They sound pretty good. There are bunch of options out there if you don't limit your search to year model 2006.
Yes I did. There is some disagreement on this though - some people say they are running the stock ECM and slip-ons with no problem. I tried it and my bike was lean. I got the Stage I download and it ran perfect until I added the SE Air Cleaner... now it's lean again. Try the slip ons and see how it runs.. it won't hurt anything and you can always get the Stage I download. If you plan to add the SE AC, then you might want to skip the download and purchase a SERT.