simota or stock?

[JapRulezz]

I am scheduled for maintainance on my yaris next week , and i thought instead of getting all of the same original aftermarket stuff what the heck , lets look for high preformance
auto parts .... and i found the simota carbon charger factory made for the yaris as a replacement for my stock air filter but some of my friends told me that the stock toyota air filter would be better than the simota carbon air intake and that the simota had wide pores that could damage my engine with dust and sand..... i also found a K&N air intake but it wasnt for the yaris it was a universal intake one and i saw it installed on a chevy aveo ....
so which one ? good old stock or simota carbon or universal K&N ?

I also found denso iridium spark plugs but i dont know if there effective or not ....... but i didnt find the lk16 i found the vk16 (which is iridium tough not iridium power)
should i search for the lk16 or install the vk16 or stick with the ordinary stuff?