Team-BHP - karizma porting

hi guys
i have an one and half year old karizma which has run 17000 kms.... i want to port my bike and i wanted to know which free flow exuast is the best? as i want to put an end can to the bike.... i would like to knw whether i should port/polish the cylinder head,and put performance spark plugs.... and the other mods i need to carry out to get a decent performance upgrade..... i am alredy running a K&n air filter.
finally i would like to know the cost involved for these mods..... thanks
happy riding.

I presume you replaced your stock jets with better flowing ones after fitting the k&n, If you havent then you've been running the engine leaner than the already lean factory standards. A classic symptom would be an overheating engine, with detonation problems.
Port polishing and stuff you could get done from guys who do car engine jobs, although the only philosophy most of them follow is make all holes bigger and mirror polish intake and exhaust for maximum flow, but that isnt it at all.
I've been reading about running gasoline engines on methanol and it seems like a really cool idea to get more bang. Only problem seems to be that methanol eats metal and rubber, atleast that's what i read. But 20-30% jump in power should be worth it right?