I have drag bars with the stock seat and pegs on my 550K. I'm tall (6'3") and it actually is more comfortable for me than the stock bars. With the stock bars and stock pegs, I felt like I was sitting on my tail bone all the time....now I'm more forward and it is more comfortable for me. Looks way better too.
FYI, if you do drag bars (the 28" type that are readily available everywhere it seems), expect to have some clearance issues with the master cylinder. You can fit it all on, but the brake handle will probably have to be angled up a bit further than you are used to.
I was just over to my friend's house the other day to help him change his bars. He is using superbike bars with the stock seat and the look is much the same as the drag bars....but they are a bit wider with just a little bit of rise. No clearance issues with those. He was going to use the 400F bars, but they are significantly more expensive.
Good luck.