Lowering and performance

[Spike11]

Hi guys just bought a 1.4 k11 I'm looking to beat it up on track really I'm looking to do it as cheap as possible. What's the cheapest/best way to lower it? Read alot about the alto spring's and corsa b shock but I can't see it being very stiff are there any other springs that can be fitted? Also power I knowill it's meant to be "80bhp" but I'd like more it's it worth doing the 1.6 injectors throttle body and air box? Thanks for any replies guys