If you have only £150 i wouldnt bother as you need one with a heat shield and a cold air feed to get it to give you the extra BHP
The best ones i can think of are,
K&N 57i Gen 2 £266.36
Simota Carbon Air Induction £199.99
Pipercross Viper £195.95
Other than them thats it for decent ones with in that price.