When should i replace my air filter
 

I have a 03 sti which i have had for just under a year. It has a pipercross cone filter fitted but i don't know how long this has been on.
Can these be cleaned or should i just replace it? I will be looking to replace it in the future but would prefer to spend the money elsewere on the car first.
When i do upgrade i was looking at either the K&N 'Short Ram' Enclosed Impreza Induction Kit or the HKS Racing Suction Impreza Induction Kit. Does anyone have any thoughts on which one i should go for or should i go for a completely different one alltogether?:wonder: