Ok. Have a 2006 heritage. It has the crossover pipe between the pipes that also serves as the exhaust mount. I have seen 07 slip ons without this crossover tube but am unable to find mounting brackets. Can someone please post the part numbers or have a solution to run 07 or later slip ons as none I find are "compatible" with an 06.

I have SE catalyst exhaust now and looking for slightly louder. I see two bolts on each pipe holding what I would think are the baffles. Maybe even just new baffles would work but eliminating the cat would be ideal to reduce heat. Those pipes really cook me when stopped.

Yes the HD stage 1 tune for AC and pipe has been done so I do not think it is too lean

 

I think that all if not most 06 and newer exhaust systems for your Heritage are going to have a crossover pipe built into the mount. I have an 06 Heritage. I also have an exhaust system off of an 2010 Heritage, it has the crossover that actually connects to the header pipes instead of the muffler, it works about the same as the 06 but is just different.
The mufflers on the 10 system don't have the crossover tube connection built into them like the 06 does. The 10 system fits on my bike just fine and has a little better sound in my opinion than the 06 does, and doesn't have a cat in either muffler. You can find slip ons that will fit your 06 with no problem here. http://epiflex.com/ I also have a set of these and they sound very good and you can get the size baffle you want to get the sound you want. Most people like the 1.75 or 2.00 baffles. By the way, the crossover pipe is your friend, without it you will feel a difference in power of the bike. If you get an aftermarket set of pipes you will be better off with a system with some sort of crossover or balance chamber in them. I have pipes with and without the balance chamber and with is better. I'm no expert but I have tried several pipes and exhaust systems on my bike over the years and the best overall so far are the Vance and Hines Big shot staggered with the "quiet" baffles. They are too loud, but the bike seems to like them and you I can feel the difference in power when they are on. It may just be that they sound more powerful too, but nevertheless it is my opinion that they work very well. It has never been on a dyno or anything although I did buy a PowerCommander tuner from a company that programmed it for my bike, it also works very well. I just wish they were a little quieter, it gets old listening to them on a trip. As I said I'm no expert and I'm not sure what info. exactly you are looking for but for what it's worth this is what has worked for me.