help, i have a bog standard impreza my01

i would want to mod it to get more power and faster acc,

however i don't want to spend more than £2k

anyone recommend anything?

is any of the following good

1, ecotek http://www.ecotekplc.com
2, power boost valve??
3, superchip
4, blitz filter
5, i would like an exhaust system however, i want a custom made back box from powerflow (imagine PS1)
i would like to leave the cat. in (can't be arsed fitting it back on when mots due

any one help please??

 

Keep your warrenty safe and get a PPP. I love mine.

Jza