If you REALLY think you MUST have more power, trade up for a bike that was designed for it.
Modern bikes often don't like being "tinkered with" and the results are BAD about as often as they are good.
I've heard that the M109 is a real beast.......just for instance.
I had a Cobra Fi2000r along with Cobra's Streetrods on my 2008. Those few things plus a Thunder Mfg, Snorkel and getting it set up on a dyno really brought my M50 to life. It's not gonna give you the rush that you'd get from a bigger bike but I was more than satisfied with the result and it won't cost anywhere near the $7k that you'd end up spending on a 10,000 mile 2007 M109. I wanted to make the bile my bike that's why I did the mods. And in my opinion, it was well worth the money.