There are a lot, and you guessed it, the market leader is the GSR F10i. Although this may be out of your budget something along the lines on the BMC CDA or Green Cotton. Just avoid the genreal muppets:- K&N and PiperX
Who ever told you the gsr induction kit was the market leader was having you on!!! Most induction kits are made using the same principles and people develop a liking for certain types based on potentially misleading information.