Ninja 250 -- -- More Horsepower

[Time]

I am trying to get really wild with the horsepower on this fine machine. I would really like to get an additional 2 to 3 hp out of this machine. I am trying to make up for all the fat I have collected in my 70 plus years. If I weighed 150 pounds, no additional horsepower would be necessary. Just think, up until I was 60 years old I did weigh around 150 pounds. I have done numerous searches and everything that I get is really vague. They are all hints but nothing really concrete.

For instance -- on exhaust mods there is only one that makes a full exhaust system and all of the others are slip on's. Some say that you must rejet on any exhaust modification and others say that you only need to rejet on the full exhaust replacement. I had much rather put a two brothers slip on system because it looks better and you can keep your center stand. When you put the full system on, it looks like you are castrated and one has hung low, but we are after performance more so than looks.

I fully intend on re-jetting the carburetors and I also intend on replacing the stock air filter -- but with what? K^N makes a drop-in filter but I have to wonder how much it will improve the airflow, what are the advantages and disadvantages of pod filters? Would pod filters be better?

Anyone have any concrete answers on any of this, it would be greatly appreciated. I know you can't get much more out of this little thing but two or three would really do the trick. In the spring I will be going back to Illinois and although it did a great job going over Cumberland Pass the last time, perhaps it will strain a little less this time.
Thanks so much in advance