I am in the market for stage 4 products for my 03 wrx. I need some advise from you. What parts do you sell that will give me a stage 4 wrx. I have a perrin uppipe, bosal downpipe and blitz catback and a mbc right now. Can you please keep in mind that I want a reliable and powerful machine. Please provide prices on parts and installation. I really dont want to use a Utec if possible. Please provide some other sort of engine mangement if available. Thank you.