Which Induction Kit, Tell Me Your Opion

i am wondering wether it is worth fitting an induction kit? My first thought was to fit a ecu spacer, are these any good?
would like to know which induction kit is the best? which gives the best sound? also if i was to fit a induction kit, what
do have have to do with the ecu as this is inside the airbox. where do i have to move it to? is it easy? and what do i need
to moved and replace it?

all help will be gratefuly received