I have a Road King also and was going to buy the rhineheart pipes, but they were very expensive. So I ended up with a pair of pythons that were around $300. They sound great! They have a great rumble at idle, and have a real bark when you get on them. But obviously, everybody has different taste with pipes, but I am very happy with my choice.
Sorry don't have any advice to give. I too am looking for help in choosing pipes for my '04 Road King. When i bought the bike it had super loud pipes ...too loud for me! ..was practically def by the time i got the bike home! :^) The seller had the stock pipes, which he included with the bike. So first thing i did was to swap out pipes for the stock ones. Of course now it's a bit too quiet.
So what I'd like is a set of pipes with some back pressure, a nice mellow tone, and decent power without requiring EFI remapping.
For example my girlfriend has an '02 Sporty with stock pipes and it sounds great to me. So i'd like to have something with a similar sound. ...and Chrome.