its not really a tough decision as you know you will get it all eventually
Milltek Cat back(with the turbo back to follow) - nice feedback when driving but Id save and get the TBE rather than 2 fitting sessions
Eibach Springs and Anti-lift kit : mmmmmmm definitely
Dbilas intake with heat shield and engine cover : thats not £400 , you could do without the cover
So thats down to
1 :TBE milltek
2 : suspension and intake
normally Id say suspension but theres a lot of benefit to hearing the ED30, when the std exhaust is soooo quiet.....